# 2018 Caroline Wozniacki tennis season

The 2018 Caroline Wozniacki tennis season officially began on 1 January 2018 with the start of the 2018 WTA Tour. Caroline Wozniacki entered the season ranked as world number 3 behind Simona Halep and Garbiñe Muguruza following the completion of the 2017 season.

## Year in detail
### Early hard court season
#### Auckland Open

Wozniacki began her season at the Auckland Open. She was the top seed and advanced to the final after successfully defeating Madison Brengle, Petra Martić, Sofia Kenin and Sachia Vickery. However, she would be defeated in straight sets by the same opponent who eliminated her in the previous year's quarterfinals, Julia Görges, in straight sets.

#### Australian Open

Her next tournament was the Australian Open. She was seeded second, her highest seeding since the 2012 Australian Open. She defeated Mihaela Buzărnescu in straight sets before going on to beat Jana Fett in three sets after saving two match points. She then beat Kiki Bertens and Magdaléna Rybáriková both in straight sets to reach the quarterfinals. In the quarterfinals, she beat Carla Suárez Navarro in three sets to advance to her second Australian Open semifinal since 2011. In the semifinals she beat Elise Mertens to advance to her third Grand Slam final and her first since 2014.
Her last opponent was Simona Halep. Wozniacki took the opening set in a tiebreak, while Halep winning the second set. The third set had the most breaks of serve. After a series of breaks, Wozniacki won two points in a row to reach championship point. Wozniacki won the point, the match and the championship, after Halep hit a backhand into the net to become the seventh woman to win the title after being match point down in Open Era.
After winning her first Grand Slam title, she regained the world No. 1 ranking on 29 January 2018. Wozniacki was last ranked No. 1 on 29 January 2012, exactly 6 years ago, and her new ascension beats Serena Williams' previous record of 5 years 29 days.

#### St. Petersburg Ladies' Trophy

Wozniacki's next tournament was the St. Petersburg Ladies' Trophy, which she entered in the second round. She defeated the young Russian, Anastasia Potapova, in straight sets before she lost to Daria Kasatkina in the quarterfinals.

#### Qatar Open

Wozniacki then played in the Qatar Open, where she received a bye in the first round. She defeated Carina Witthöft with a bagel in the second set. The Australian Open champion put together a dominant performance and needed just 57 minutes to record the victory. She then defeated Monica Niculescu in straight sets to extend her head-to-head advantage to 9–0 over the Romanian. Her next opponent was former world No. 1, Angelique Kerber. Kerber got out to a fast start but the first set went to a tiebreak and ended in Wozniacki's favour. Kerber easily won set two. The third set was a marathon of long rallies but Wozniacki won in a gruelling two hours and 20 minutes. Against Petra Kvitová, Wozniacki wasn't so lucky. She lost, despite having two chances to serve for the match. However, with her Qatar performance, she became only the fourth player in WTA history to surpass $30,000,000 in career prize earnings.

### March sunshine events
#### Indian Wells Open

Wozniacki then played the Indian Wells Open, where she received a bye in the first round. She defeated Lara Arruabarrena and Aliaksandra Sasnovich, in straight sets and three sets respectively before she lost to Daria Kasatkina again in the fourth round.

#### Miami Open

Wozniacki then entered the Miami Open, where she also received a bye in the first round. However, she lost to the Summer Olympics champion Monica Puig in three sets after sending a bagel in the opening set.

### European clay court season
#### İstanbul Cup

Wozniacki started her 2018 clay season in the İstanbul Cup, where she defeated Ekaterina Alexandrova and Sara Errani in straight sets and three sets respectively. However, she chose to retire from the event against the eventual winner Pauline Parmentier in the quarterfinals.

#### Madrid Open

Wozniacki then played the Madrid Open. She defeated two Australians, Daria Gavrilova and Ashleigh Barty, and advanced into the third round. However, she lost to the eventual runner-up Kiki Bertens, who was defeated in the Australian Open, in straight sets.

#### Italian Open

Wozniacki's next tournament was the Italian Open, where she received a bye in the first round. She defeated Alison Van Uytvanck in straight sets in the second round and Anastasija Sevastova in three sets in the third round respectively before she lost to Anett Kontaveit in straight sets in the quarterfinals.

#### French Open

In the French Open, Wozniacki was the 2nd seed. In the first round, she defeated Danielle Collins after the opening-set tiebreak. In the second round, she easily defeated the Spanish qualifier Georgina García Pérez in just fifty minutes. Her opponent in the third round was the local people Pauline Parmentier, who just defeated Caroline couple of weeks ago on the way to her first WTA title since 2008. Wozniacki defeated the Frenchwoman in straight sets after sending a bagel in the opening set. Her next opponent was the 14th seed Daria Kasatkina, who defeated Wozniacki twice this year. Wozniacki eventually lost to the Russian in straight sets again after the match delayed to Monday.

### United Kingdom grass court Season
#### Eastbourne International

Wozniacki started her 2018 grass season in the Eastbourne International, where she was the runner-up last year. She started her competition in the second round, where she defeated Camila Giorgi. In the third round, she defeated Johanna Konta for the first time in her career, in three sets. After defeating Ashleigh Barty in straight sets, she reached the semi-finals for the fifth time in six years. She successfully defeated Angelique Kerber in three sets after saving a match point to advance into final. Her final opponent of the tournament was Aryna Sabalenka and the match was their first meet. Eventually, the Dane defeated the Byelorussian to win her second title of the year, and her 29th overall. The final also marked her 600th career match win.

#### Wimbledon Championships

Wozniacki then played in the Wimbledon Championships, where she was seeded second. In the first round, she successfully defeated Varvara Lepchenko after sending a bagel. However, she lost to Ekaterina Makarova, who defeated Wozniacki in the US Open also in the second round last year, in three sets despite saving five match points.

### Summer US Open series
#### Washington Open

Wozniacki was scheduled to participate in the Washington Open, where she was supposed to be the top seed, but she was forced to retired before her first-round match against Anhelina Kalinina due to a right leg injury.

#### Canadian Open

After the retirement in Washington, she then participated in the Canadian Open, where she received a bye in the first round. Her first opponent was Aryna Sabalenka, who was defeated in the final of Eastbourne in straight sets. However, this time she lost to the Belarusian in three sets after wasting three match points.

#### Cincinnati Open

At Cincinnati, Wozniacki retired against the eventual winner Kiki Bertens in her first match of the tournament after losing the opening set because of a left knee injury.

#### US Open

In the US Open, Wozniacki defeated former champion Samantha Stosur in straight sets before she lost to Lesia Tsurenko in the second round.

### East Asian hardcourt season
#### Toray Pan Pacific Open

In fall, Wozniacki played the Pan Pacific Open, where she was the top seed, by receiving a wildcard as the defending champion. However, she lost to Camila Giorgi in three sets in the second round.

#### Wuhan Open

A week later, in Wuhan, Wozniacki was upset by Monica Puig for the second time this season in straight sets in third round after defeated qualifier Rebecca Peterson.

#### China Open

Wozniacki then played the China Open. In the first round, she defeated Belinda Bencic, who had a small advantage on head-to-head, in straight sets. Then she defeated Petra Martić for the second time this year in straight sets. In the third round, She successfully defeated Anett Kontaveit, who defeated the Dann at Montreal in straight sets. In the semifinals, she upset local favourite Wang Qiang in straight sets. In the final, she successfully held off Anastasija Sevastova to win the China Open title for the second time in her career without losing a set. This was also her first Premier Mandatory level title since winning the 2011 BNP Paribas Open and her 30th WTA title.

### Year-end Championships
#### WTA Finals

After reaching the quarterfinals in Beijing in her last tournament, Wozniacki became the fifth player to secure Singapore spot. As the second seed, she led the White Group, alongside Petra Kvitová, Elina Svitolina and Karolína Plíšková. However, her road to defend her title didn't start very well. In her first round robin match, she lost to World No. 7 Karolína Plíšková in straight sets after saving two match points. She then defeated Petra Kvitová in three sets before was upset by Elina Svitolina. The outcome made her finished third in the group, which meant she was unable to advance into the semifinals.
After eliminating in the round robin, Wozniacki announced that she was diagnosed with Rheumatoid arthritis, but would like to become a role model for people with the condition. Nevertheless, she still finished the season as World No. 3.

## All matches

Key :
| W | F | SF | QF | #R | RR | Q# | P# | DNQ | A | Z# | PO | G | S | B | NMS | NTI | P | NH |

### Singles matches

| Tournament | Match | Round | Opponent | Rank | Result | Score |
| Auckland Open Auckland, New Zealand WTA International Hard, outdoor 1–7 January 2018 | 1 | 1R | Madison Brengle | 85 | Win | 6–3, 6–0 |
| Auckland Open Auckland, New Zealand WTA International Hard, outdoor 1–7 January 2018 | 2 | 2R | Petra Martić | 90 | Win | 6–2, 6–2 |
| Auckland Open Auckland, New Zealand WTA International Hard, outdoor 1–7 January 2018 | 3 | QF | Sofia Kenin (WC) | 108 | Win | 4–6, 6–2, 6–4 |
| Auckland Open Auckland, New Zealand WTA International Hard, outdoor 1–7 January 2018 | 4 | SF | Sachia Vickery (Q) | 122 | Win | 6–4, 6–4 |
| Auckland Open Auckland, New Zealand WTA International Hard, outdoor 1–7 January 2018 | 5 | F | Julia Görges (2) | 14 | Loss (1) | 4–6, 6–7$^{(2–7)}$ |
| Australian Open Melbourne, Australia Grand Slam Hard, outdoor 15–28 January 2018 | 6 | 1R | Mihaela Buzărnescu | 44 | Win | 6–2, 6–3 |
| Australian Open Melbourne, Australia Grand Slam Hard, outdoor 15–28 January 2018 | 7 | 2R | Jana Fett | 119 | Win | 3–6, 6–2, 7–5 |
| Australian Open Melbourne, Australia Grand Slam Hard, outdoor 15–28 January 2018 | 8 | 3R | Kiki Bertens (30) | 32 | Win | 6–4, 6–3 |
| Australian Open Melbourne, Australia Grand Slam Hard, outdoor 15–28 January 2018 | 9 | 4R | Magdaléna Rybáriková (19) | 21 | Win | 6–3, 6–0 |
| Australian Open Melbourne, Australia Grand Slam Hard, outdoor 15–28 January 2018 | 10 | QF | Carla Suárez Navarro | 39 | Win | 6–0, 6–7$^{(3–7)}$, 6–2 |
| Australian Open Melbourne, Australia Grand Slam Hard, outdoor 15–28 January 2018 | 11 | SF | Elise Mertens | 37 | Win | 6–3, 7–6$^{(7–2)}$ |
| Australian Open Melbourne, Australia Grand Slam Hard, outdoor 15–28 January 2018 | 12 | W | Simona Halep (1) | 1 | Win (1) | 7–6$^{(7–2)}$, 3–6, 6–4 |
| St. Petersburg Ladies' Trophy Saint Petersburg, Russia WTA Premier Hard, indoor 29 January – 4 February 2018 | – | 1R | Bye | Bye | Bye | Bye |
| St. Petersburg Ladies' Trophy Saint Petersburg, Russia WTA Premier Hard, indoor 29 January – 4 February 2018 | 13 | 2R | Anastasia Potapova (WC) | 235 | Win | 6–0, 6–1 |
| St. Petersburg Ladies' Trophy Saint Petersburg, Russia WTA Premier Hard, indoor 29 January – 4 February 2018 | 14 | QF | Daria Kasatkina (8) | 23 | Loss | 6–7$^{(2–7)}$, 3–6 |
| Qatar Open Doha, Qatar WTA Premier 5 Hard, outdoor 12–17 February 2018 | – | 1R | Bye | Bye | Bye | Bye |
| Qatar Open Doha, Qatar WTA Premier 5 Hard, outdoor 12–17 February 2018 | 15 | 2R | Carina Witthöft | 52 | Win | 6–2, 6–0 |
| Qatar Open Doha, Qatar WTA Premier 5 Hard, outdoor 12–17 February 2018 | 16 | 3R | Monica Niculescu (Q) | 92 | Win | 7–5, 6–1 |
| Qatar Open Doha, Qatar WTA Premier 5 Hard, outdoor 12–17 February 2018 | 17 | QF | Angelique Kerber (8) | 9 | Win | 7–6$^{(7–4)}$, 1–6, 6–3 |
| Qatar Open Doha, Qatar WTA Premier 5 Hard, outdoor 12–17 February 2018 | 18 | SF | Petra Kvitová (16) | 21 | Loss | 6–3, 6–7$^{(3–7)}$, 5–7 |
| Indian Wells Open Indian Wells, United States WTA Premier Mandatory Hard, outdoor 5–18 March 2018 | – | 1R | Bye | Bye | Bye | Bye |
| Indian Wells Open Indian Wells, United States WTA Premier Mandatory Hard, outdoor 5–18 March 2018 | 19 | 2R | Lara Arruabarrena (Q) | 80 | Win | 6–4, 6–1 |
| Indian Wells Open Indian Wells, United States WTA Premier Mandatory Hard, outdoor 5–18 March 2018 | 20 | 3R | Aliaksandra Sasnovich | 49 | Win | 6–4, 2–6, 6–3 |
| Indian Wells Open Indian Wells, United States WTA Premier Mandatory Hard, outdoor 5–18 March 2018 | 21 | 4R | Daria Kasatkina (20) | 19 | Loss | 4–6, 5–7 |
| Miami Open Miami, United States WTA Premier Mandatory Hard, outdoor 19 March – 1 April 2018 | – | 1R | Bye | Bye | Bye | Bye |
| Miami Open Miami, United States WTA Premier Mandatory Hard, outdoor 19 March – 1 April 2018 | 22 | 2R | Monica Puig | 82 | Loss | 6–0, 4–6, 4–6 |
| İstanbul Cup Istanbul, Turkey WTA International Clay, outdoor 23–29 April 2018 | 23 | 1R | Ekaterina Alexandrova | 82 | Win | 6–2, 6–2 |
| İstanbul Cup Istanbul, Turkey WTA International Clay, outdoor 23–29 April 2018 | 24 | 2R | Sara Errani | 93 | Win | 5–7, 6–3, 6–3 |
| İstanbul Cup Istanbul, Turkey WTA International Clay, outdoor 23–29 April 2018 | 25 | QF | Pauline Parmentier | 122 | Loss | 6–4, 3–6 retired |
| Madrid Open Madrid, Spain WTA Premier Mandatory Clay, outdoor 7–13 May 2018 | 26 | 1R | Daria Gavrilova | 24 | Win | 6–3, 6–1 |
| Madrid Open Madrid, Spain WTA Premier Mandatory Clay, outdoor 7–13 May 2018 | 27 | 2R | Ashleigh Barty | 18 | Win | 6–2, 4–6, 6–4 |
| Madrid Open Madrid, Spain WTA Premier Mandatory Clay, outdoor 7–13 May 2018 | 28 | 3R | Kiki Bertens | 20 | Loss | 2–6, 2–6 |
| Italian Open Rome, Italy WTA Premier 5 Clay, outdoor 14–20 May 2018 | – | 1R | Bye | Bye | Bye | Bye |
| Italian Open Rome, Italy WTA Premier 5 Clay, outdoor 14–20 May 2018 | 29 | 2R | Alison Van Uytvanck | 49 | Win | 6–4, 6–1 |
| Italian Open Rome, Italy WTA Premier 5 Clay, outdoor 14–20 May 2018 | 30 | 3R | Anastasija Sevastova (15) | 20 | Win | 6–2, 5–7, 6–3 |
| Italian Open Rome, Italy WTA Premier 5 Clay, outdoor 14–20 May 2018 | 31 | QF | Anett Kontaveit | 23 | Loss | 3–6, 1–6 |
| French Open Paris, France Grand Slam Clay, outdoor 27 May –10 June 2018 | 32 | 1R | Danielle Collins | 41 | Win | 7–6$^{(7–2)}$, 6–1 |
| French Open Paris, France Grand Slam Clay, outdoor 27 May –10 June 2018 | 33 | 2R | Georgina García Pérez (Q) | 186 | Win | 6–1, 6–0 |
| French Open Paris, France Grand Slam Clay, outdoor 27 May –10 June 2018 | 34 | 3R | Pauline Parmentier (WC) | 74 | Win | 6–0, 6–3 |
| French Open Paris, France Grand Slam Clay, outdoor 27 May –10 June 2018 | 35 | 4R | Daria Kasatkina (14) | 14 | Loss | 6–7$^{(5–7)}$, 3–6 |
| Eastbourne International Eastbourne, United Kingdom WTA Premier Grass, indoor 24–30 June 2018 | – | 1R | Bye | Bye | Bye | Bye |
| Eastbourne International Eastbourne, United Kingdom WTA Premier Grass, indoor 24–30 June 2018 | 36 | 2R | Camila Giorgi | 56 | Win | 6–2, 6–3 |
| Eastbourne International Eastbourne, United Kingdom WTA Premier Grass, indoor 24–30 June 2018 | 37 | 3R | Johanna Konta (13) | 22 | Win | 4–6, 6–1, 6–4 |
| Eastbourne International Eastbourne, United Kingdom WTA Premier Grass, indoor 24–30 June 2018 | 38 | QF | Ashleigh Barty (8) | 17 | Win | 6–4, 6–3 |
| Eastbourne International Eastbourne, United Kingdom WTA Premier Grass, indoor 24–30 June 2018 | 39 | SF | Angelique Kerber (4) | 11 | Win | 2–6, 7–6$^{(7–4)}$, 6–4 |
| Eastbourne International Eastbourne, United Kingdom WTA Premier Grass, indoor 24–30 June 2018 | 40 | W | Aryna Sabalenka | 45 | Win (2) | 7–5, 7–6$^{(7–5)}$ |
| Wimbledon Championships London, United Kingdom Grand Slam Grass, outdoor 2 –15 July 2018 | 41 | 1R | Varvara Lepchenko | 97 | Win | 6–0, 6–3 |
| Wimbledon Championships London, United Kingdom Grand Slam Grass, outdoor 2 –15 July 2018 | 42 | 2R | Ekaterina Makarova | 35 | Loss | 4–6, 6–1, 5–7 |
| Washington Open Washington, D.C., United States WTA International Hard, outdoor 30 July –5 August 2018 | – | 1R | Anhelina Kalinina (Q) | 143 | Withdrew | N/A |
| Canadian Open Montreal, Canada WTA Premier 5 Hard, outdoor 6–12 August 2018 | – | 1R | Bye | Bye | Bye | Bye |
| Canadian Open Montreal, Canada WTA Premier 5 Hard, outdoor 6–12 August 2018 | 43 | 2R | Aryna Sabalenka | 39 | Loss | 7–5, 2–6, 6–7$^{(4–7)}$ |
| Cincinnati Open Cincinnati, United States WTA Premier 5 Hard, outdoor 13–19 August 2018 | – | 1R | Bye | Bye | Bye | Bye |
| Cincinnati Open Cincinnati, United States WTA Premier 5 Hard, outdoor 13–19 August 2018 | 44 | 2R | Kiki Bertens | 17 | Loss | 4–6 retired |
| U.S. Open New York City, United States Grand Slam Hard, outdoor 27 August – 9 September 2018 | 45 | 1R | Samantha Stosur | 64 | Win | 6–3, 6–2 |
| U.S. Open New York City, United States Grand Slam Hard, outdoor 27 August – 9 September 2018 | 46 | 2R | Lesia Tsurenko | 36 | Loss | 4–6, 2–6 |
| Pan Pacific Open Tokyo, Japan WTA Premier Hard, indoor 17–23 September 2018 | – | 1R | Bye | Bye | Bye | Bye |
| Pan Pacific Open Tokyo, Japan WTA Premier Hard, indoor 17–23 September 2018 | 47 | 2R | Camila Giorgi | 37 | Loss | 2–6, 6–2, 4–6 |
| Wuhan Open Wuhan, China WTA Premier 5 Hard, outdoor 23–29 September 2018 | – | 1R | Bye | Bye | Bye | Bye |
| Wuhan Open Wuhan, China WTA Premier 5 Hard, outdoor 23–29 September 2018 | 48 | 2R | Rebecca Peterson (Q) | 61 | Win | 6–4, 6–1 |
| Wuhan Open Wuhan, China WTA Premier 5 Hard, outdoor 23–29 September 2018 | 49 | 3R | Monica Puig (Q) | 51 | Loss | 6–7$^{(10–12)}$, 5–7 |
| China Open Beijing, China WTA Premier Mandatory Hard, outdoor 1–7 October 2018 | 50 | 1R | Belinda Bencic | 42 | Win | 6–2, 6–3 |
| China Open Beijing, China WTA Premier Mandatory Hard, outdoor 1–7 October 2018 | 51 | 2R | Petra Martić | 37 | Win | 7–5, 6–3 |
| China Open Beijing, China WTA Premier Mandatory Hard, outdoor 1–7 October 2018 | 52 | 3R | Anett Kontaveit | 21 | Win | 7–5, 6–4 |
| China Open Beijing, China WTA Premier Mandatory Hard, outdoor 1–7 October 2018 | 53 | QF | Kateřina Siniaková (Q) | 40 | Win | 6–2, 6–2 |
| China Open Beijing, China WTA Premier Mandatory Hard, outdoor 1–7 October 2018 | 54 | SF | Wang Qiang (WC) | 28 | Win | 6–1, 6–3 |
| China Open Beijing, China WTA Premier Mandatory Hard, outdoor 1–7 October 2018 | 55 | W | Anastasija Sevastova | 20 | Win (3) | 6–3, 6–3 |
| WTA Finals Kallang, Singapore Year-end championships Hard, indoor 21–28 October 2018 | 56 | RR | Karolína Plíšková (7) | 8 | Loss | 2–6, 4–6 |
| WTA Finals Kallang, Singapore Year-end championships Hard, indoor 21–28 October 2018 | 57 | RR | Petra Kvitová (4) | 5 | Win | 7–5, 3–6, 6–2 |
| WTA Finals Kallang, Singapore Year-end championships Hard, indoor 21–28 October 2018 | 58 | RR | Elina Svitolina (6) | 7 | Loss | 7–5, 5–7, 3–6 |

## Tournament schedule
### Singles schedule

Wozniacki's 2018 singles tournament schedule is as follows:
| Date | Tournament | Location | Category | Surface | 2017 result | 2017 points | 2018 points | Result |
| 1 January – 7 January | Auckland Open | New Zealand | International | Hard | QF | 60 | 180 | Final lost to Julia Görges 4–6, 6–7$^{(2–7)}$ |
| 15 January – 28 January | Australian Open | Australia | Grand Slam | Hard | 3R | 130 | 2000 | Winner defeated Simona Halep 7–6$^{(7–2)}$, 3–6, 6–4 |
| 29 January – 4 February | St. Petersburg Ladies' Trophy | Russia | Premier | Hard (i) | DNP | 0 | 100 | Quarterfinals lost to Daria Kasatkina 6–7$^{(2–7)}$, 3–6 |
| 12 February – 17 February | Qatar Open | Qatar | Premier 5 | Hard | F | 305 | 350 | Semifinals lost to Petra Kvitová 6–3, 6–7$^{(3–7)}$, 5–7 |
| 5 March – 18 March | Indian Wells Open | United States | Premier Mandatory | Hard | QF | 215 | 120 | Fourth round lost to Daria Kasatkina 4–6, 5–7 |
| 19 March – 1 April | Miami Open | United States | Premier Mandatory | Hard | F | 650 | 10 | Second round lost to Monica Puig 6–0, 4–6, 4–6 |
| 23 April – 29 April | İstanbul Cup | Turkey | International | Clay | DNP | 0 | 60 | Quarterfinals lost to Pauline Parmentier 6–4, 3–6 retired |
| 7 May – 13 May | Madrid Open | Spain | Premier Mandatory | Clay | 2R | 65 | 120 | Third round lost to Kiki Bertens 2–6, 2–6 |
| 14 May – 20 May | Italian Open | Italy | Premier 5 | Clay | DNP | 0 | 190 | Quarterfinals lost to Anett Kontaveit 3–6, 1–6 |
| 27 May – 10 June | French Open | France | Grand Slam | Clay | QF | 430 | 240 | Fourth round lost to Daria Kasatkina 6–7$^{(5–7)}$, 3–6 |
| 24 June – 30 June | Eastbourne International | United Kingdom | Premier | Grass | F | 305 | 470 | Winner defeated Aryna Sabalenka 7–5, 7–6$^{(7–5)}$ |
| 2 July – 15 July | Wimbledon Championships | United Kingdom | Grand Slam | Grass | 4R | 240 | 70 | Second round lost to Ekaterina Makarova 4–6, 6–1, 5–7 |
| 30 July – 5 August | Washington Open | United States | International | Hard | DNP | 0 | 0 | Withdrew due to leg injury |
| 6 August – 12 August | Canadian Open | Canada | Premier 5 | Hard | F | 585 | 1 | Second round lost to Aryna Sabalenka 7–5, 2–6, 6–7$^{(4–7)}$ |
| 13 August – 19 August | Cincinnati Open | United States | Premier 5 | Hard | QF | 190 | 1 | Second round lost to Kiki Bertens 4–6 retired |
| 27 August – 9 September | U.S. Open | United States | Grand Slam | Hard | 2R | 70 | 70 | Second round lost to Lesia Tsurenko 4–6, 2–6 |
| 17 September – 23 September | Pan Pacific Open | Japan | Premier | Hard (i) | W | 470 | 1 | Second round lost to Camila Giorgi 2–6, 6–2, 4–6 |
| 13 August – 19 August | Wuhan Open | China | Premier 5 | Hard | 2R | 1 | 105 | Third round lost to Monica Puig 6–7$^{(10–12)}$, 5–7 |
| 1 October – 7 October | China Open | China | Premier Mandatory | Hard | 3R | 120 | 1000 | Winner defeated Anastasija Sevastova 6–3, 6–3 |
| 21 October – 28 October | WTA Finals | Singapore | Year-end Championships | Hard (i) | W | 1375 | 500 | Failed to advance into the semifinals 1 won & 2 losses |
| Road to Singapore points | Road to Singapore points | Road to Singapore points | Road to Singapore points | Road to Singapore points | Road to Singapore points | 4640 | 5086 | 446 difference |
| Total year-end points | Total year-end points | Total year-end points | Total year-end points | Total year-end points | Total year-end points | 6015 | 5586 | 429 difference |

## Yearly records
### Head-to-head matchups

| Surface | Win–loss | Win% |
| Hard | 26–12 | 68.42% |
| Clay | 9–4 | 69.23% |
| Grass | 6–1 | 85.71% |
| Overall | 41–17 | 70.69% |
Players are ordered by letter.
| Player | Rank | Tournament | Surface | Date | W/L | W–L | CWR |
| Aliaksandra Sasnovich | 49 | Indian Wells Masters, Indian Wells, United States | Hard | March 2, 2018 | Win | 1–0 | 2 |
| Alison Van Uytvanck | 49 | Italian Open, Rome, Italy | Clay | May 15, 2018 | Win | 1–0 | 2 |
| Anastasia Potapova | 235 | St. Petersburg Ladies' Trophy, Saint Petersburg, Russia | Hard (i) | February 1, 2018 | Win | 1–0 | 1 |
| Anastasija Sevastova | 20 | Italian Open, Rome, Italy | Clay | May 16, 2018 | Win | 2–0 | 2 |
| Anastasija Sevastova | 20 | China Open, Beijing, China | Hard | October 7, 2018 | Win | 2–0 | 2 |
| Anett Kontaveit | 23 | Italian Open, Rome, Italy | Clay | May 18, 2018 | Loss | 1–1 | 2 |
| Anett Kontaveit | 21 | China Open, Beijing, China | Hard | October 4, 2018 | Win | 1–1 | 2 |
| Angelique Kerber | 9 | Qatar Open, Doha, Qatar | Hard | February 16, 2018 | Win | 2–0 | 1 |
| Angelique Kerber | 11 | Eastbourne International, Eastbourne, United Kingdom | Grass | June 29, 2018 | Win | 2–0 | 2 |
| Aryna Sabalenka | 45 | Eastbourne International, Eastbourne, United Kingdom | Grass | June 30, 2018 | Win | 1–1 | 2 |
| Aryna Sabalenka | 39 | Canadian Open, Toronto, Canada | Hard | August 9, 2018 | Loss | 1–1 | 2 |
| Ashleigh Barty | 18 | Mutua Madrid Open, Madrid, Spain | Clay | May 7, 2018 | Win | 2–0 | 2 |
| Ashleigh Barty | 17 | Eastbourne International, Eastbourne, United Kingdom | Grass | June 28, 2018 | Win | 2–0 | 2 |
| Belinda Bencic | 42 | China Open, Beijing, China | Hard | October 1, 2018 | Win | 1–0 | 2 |
| Camila Giorgi | 56 | Eastbourne International, Eastbourne, United Kingdom | Grass | June 25, 2018 | Win | 1–1 | 2 |
| Camila Giorgi | 37 | Pan Pacific Open, Tokyo, Japan | Hard (i) | September 20, 2018 | Loss | 1–1 | 2 |
| Carla Suárez Navarro | 39 | Australian Open, Melbourne, Australia | Hard | January 23, 2018 | Win | 1–0 | 2 |
| Danielle Collins | 41 | French Open, Paris, France | Clay | May 28, 2018 | Win | 1–0 | 2 |
| Daria Gavrilova | 24 | Mutua Madrid Open, Madrid, Spain | Clay | May 6, 2018 | Win | 1–0 | 2 |
| Daria Kasatkina | 23 | St. Petersburg Ladies' Trophy, Saint Petersburg, Russia | Hard (i) | February 2, 2018 | Loss | 0–3 | 1 |
| Daria Kasatkina | 19 | Indian Wells Masters, Indian Wells, United States | Hard | March 14, 2018 | Loss | 0–3 | 2 |
| Daria Kasatkina | 14 | French Open, Paris, France | Clay | June 4, 2018 | Loss | 0–3 | 2 |
| Ekaterina Alexandrova | 82 | İstanbul Cup, Istanbul, Turkey | Clay | April 24, 2018 | Win | 1–0 | 2 |
| Ekaterina Makarova | 35 | Wimbledon Championships, London, United Kingdom | Grass | July 4, 2018 | Loss | 0–1 | 2 |
| Elina Svitolina | 7 | WTA Finals, Kallang, Singapore | Hard (i) | October 25, 2018 | Loss | 0–1 | 3 |
| Elise Mertens | 37 | Australian Open, Melbourne, Australia | Hard | January 25, 2018 | Win | 1–0 | 2 |
| Georgina García Pérez | 186 | French Open, Paris, France | Clay | May 30, 2018 | Win | 1–0 | 2 |
| Jana Fett | 119 | Australian Open, Melbourne, Australia | Hard | January 17, 2018 | Win | 1–0 | 2 |
| Johanna Konta | 22 | Eastbourne International, Eastbourne, United Kingdom | Grass | June 27, 2018 | Win | 1–0 | 2 |
| Julia Görges | 14 | Auckland Open, Auckland, New Zealand | Hard | January 7, 2018 | Loss | 0–1 | 3 |
| Kateřina Siniaková | 40 | China Open, Beijing, China | Hard | October 5, 2018 | Win | 1–0 | 2 |
| Karolína Plíšková | 8 | WTA Finals, Kallang, Singapore | Hard (i) | October 21, 2018 | Loss | 0–1 | 2 |
| Kiki Bertens | 32 | Australian Open, Melbourne, Australia | Hard | January 19, 2018 | Win | 1–2 | 2 |
| Kiki Bertens | 20 | Mutua Madrid Open, Madrid, Spain | Clay | May 9, 2018 | Loss | 1–2 | 2 |
| Kiki Bertens | 17 | Cincinnati Open, Cincinnati, United States | Hard | August 15, 2018 | Loss | 1–2 | 2 |
| Lara Arruabarrena | 80 | Indian Wells Masters, Indian Wells, United States | Hard | March 3, 2018 | Win | 1–0 | 2 |
| Lesia Tsurenko | 36 | U.S. Open, New York City, United States | Hard | August 30, 2018 | Win | 0–1 | 2 |
| Madison Brengle | 85 | Auckland Open, Auckland, New Zealand | Hard | January 2, 2018 | Win | 1–0 | 3 |
| Magdaléna Rybáriková | 21 | Australian Open, Melbourne, Australia | Hard | January 21, 2018 | Win | 1–0 | 2 |
| Mihaela Buzărnescu | 44 | Australian Open, Melbourne, Australia | Hard | January 15, 2018 | Win | 1–0 | 2 |
| Monica Niculescu | 92 | Qatar Open, Doha, Qatar | Hard | February 15, 2018 | Win | 1–0 | 1 |
| Monica Puig | 82 | Miami Open, Miami, United States | Hard | March 24, 2018 | Loss | 0–2 | 2 |
| Monica Puig | 51 | Wuhan Open, Wuhan, China | Hard | September 26, 2018 | Loss | 0–2 | 2 |
| Pauline Parmentier | 122 | İstanbul Cup, Istanbul, Turkey | Clay | April 27, 2018 | Loss | 1–1 | 2 |
| Pauline Parmentier | 74 | French Open, Paris, France | Clay | June 1, 2018 | Win | 1–1 | 2 |
| Petra Kvitová | 21 | Qatar Open, Doha, Qatar | Hard | February 17, 2018 | Loss | 1–1 | 1 |
| Petra Kvitová | 5 | WTA Finals, Kallang, Singapore | Hard (i) | October 23, 2018 | Win | 1–1 | 3 |
| Petra Martić | 90 | Auckland Open, Auckland, New Zealand | Hard | January 3, 2018 | Win | 2–0 | 3 |
| Petra Martić | 37 | China Open, Beijing, China | Hard | October 3, 2018 | Win | 2–0 | 2 |
| Rebecca Peterson | 61 | Wuhan Open, Wuhan, China | Hard | September 25, 2018 | Win | 1–0 | 2 |
| Sachia Vickery | 122 | Auckland Open, Auckland, New Zealand | Hard | January 6, 2018 | Win | 1–0 | 3 |
| Samantha Stosur | 64 | U.S. Open, New York City, United States | Hard | August 28, 2018 | Win | 1–0 | 2 |
| Sara Errani | 93 | İstanbul Cup, Istanbul, Turkey | Clay | April 26, 2018 | Win | 1–0 | 2 |
| Simona Halep | 1 | Australian Open, Melbourne, Australia | Hard | January 27, 2018 | Win | 1–0 | 2 |
| Sofia Kenin | 108 | Auckland Open, Auckland, New Zealand | Hard | January 6, 2018 | Win | 1–0 | 3 |
| Varvara Lepchenko | 97 | Wimbledon Championships, London, United Kingdom | Grass | July 2, 2018 | Win | 1–0 | 2 |
| Wang Qiang | 28 | China Open, Beijing, China | Hard | October 6, 2018 | Win | 1–0 | 2 |

### Top 10 wins

| # | Player | Rank | Tournament | Surface | Round | Score | CWR |
| 1. | Simona Halep | 1 | Australian Open, Melbourne, Australia | Hard | Final | 7–6$^{(7–2)}$, 3–6, 6–4 | 2 |
| 2. | Angelique Kerber | 9 | Qatar Open, Doha, Qatar | Hard | Quarterfinals | 7–6$^{(7–4)}$, 1–6, 6–3 | 1 |
| 3. | Petra Kvitová | 5 | WTA Finals, Kallang, Singapore | Hard (i) | Round robin | 7–5, 3–6, 6–2 | 3 |

### Finals

Singles: 4 (3 titles, 1 runner-up)
* Legend
* Grand Slam tournaments (1–0)
* WTA Tour Championships (0–0)
* Premier Mandatory & Premier 5 (1–0)
* Premier (1–0)
* International (0–1)
* Finals by surface
* Hard (2–1)
* Clay (0–0)
* Grass (1–0)
* Titles by setting
* Outdoors (3–1)
* Indoors (0–0)
| Result | W–L | Date | Tournament | Tier | Surface | Opponent | Score |
| Loss | 0–1 | Jan 2018 | Auckland Open, New Zealand | International | Hard | Julia Görges | 4–6, 6–7$^{(4–7)}$ |
| Win | 1–1 | Jan 2018 | Australian Open, Australia | Grand Slam | Hard | Simona Halep | 7–6$^{(7–2)}$, 3–6, 6–4 |
| Win | 2–1 | Jun 2018 | Eastbourne International, United Kingdom | Premier | Grass | Aryna Sabalenka | 7–5, 7–6$^{(7–5)}$ |
| Win | 3–1 | Oct 2018 | China Open, China | Premier M | Hard | Anastasija Sevastova | 6–3, 6–3 |

### Earnings

The tournaments won by Wozniacki are in boldface.
| # | Tournament | Prize money | Year-to-date |
| 1. | Auckland Open | US$21,400 | $21,400 |
| 2. | Australian Open | A$4,000,000 | $3,056,344 |
| 3. | St. Petersburg Ladies' Trophy | $21,010 | $3,077,354 |
| 4. | Qatar Open | $147,750 | $3,225,104 |
| 5. | Indian Wells Masters | $88,135 | $3,313,239 |
| 6. | Miami Open | $25,465 | $3,338,704 |
| 7. | İstanbul Cup | $6,175 | $3,344,879 |
| 8. | Mutua Madrid Open | €77,575 | $3,436,463 |
| 9. | Italian Open | €58,313 | $3,508,771 |
| 10. | French Open | €222,000 | $3,769,896 |
| 11. | Eastbourne International | $140,400 | $3,928,666 |
| 12. | Wimbledon Championships | £63,000 | $4,015,439 |
| – | Washington Open | — | $4,015,439 |
| 13. | Canadian Open | $8,015 | $4,030,299 |
| 14. | Cincinnati Open | $7,745 | $4,045,479 |
| 15. | US Open | $93,000 | $4,138,479 |
| 16. | Toray Pan Pacific Open | $11,265 | $4,149,744 |
| 17. | Wuhan Open | $13,790 | $4,178,474 |
| 18. | China Open | $1,525,245 | $5,703,719 |
| 19. | WTA Finals | $304,000 | $6,007,719 |
| Bonus Pool | Bonus Pool | $650,000 | $6,657,719 |
| Total prize money | Total prize money | Total prize money | $6,657,719 |