# 2018 Porsche Tennis Grand Prix – Singles

Laura Siegemund was the defending champion, but lost in the second round to CoCo Vandeweghe.
Karolína Plíšková won the title, defeating Vandeweghe in the final, 7–6$^{(7–2)}$, 6–4.
15-year-old Marta Kostyuk became the youngest player to win a main draw match in Stuttgart since Martina Hingis in October 1994.

## Seeds

The top four seeds received a bye into the second round.
* Simona Halep (quarterfinals)
* Garbiñe Muguruza (second round, retired)
* Elina Svitolina (quarterfinals)
* Jeļena Ostapenko (quarterfinals)
* Karolína Plíšková (champion)
* Caroline Garcia (semifinals)
* Sloane Stephens (first round)
* Petra Kvitová (first round)

## Draw
### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* Alt = Alternate
* SE = Special exempt
* PR = Protected ranking
* ITF = ITF entry
* JE = Junior exempt
* w/o = Walkover
* r = Retired
* d = Defaulted
* SR = Special ranking

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final |
| WC | CoCo Vandeweghe | 6 | 6 | | | | |
| 6 | Caroline Garcia | 4 | 2 | | | | |
| 6 | Caroline Garcia | 4 | 2 | WC | CoCo Vandeweghe | 6$^2$ | 4 |
| | | | | 5 | Karolína Plíšková | 7$^7$ | 6 |
| 5 | Karolína Plíšková | 6 | 6 | 5 | Karolína Plíšková | 7$^7$ | 6 |
| | Anett Kontaveit | 4 | 2 | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| | | | | | 1 | S Halep | 4 | 6 | 6 | | | | | | | | | |
| | D Kasatkina | 2 | 2 | | | M Rybáriková | 6 | 2 | 3 | | | | | | | | | |
| | M Rybáriková | 6 | 6 | | | | | | | 1 | S Halep | 4 | 1 | | | | | |
| | B Strýcová | 4 | 3 | | | | | | | WC | C Vandeweghe | 6 | 6 | | | | | |
| WC | L Siegemund | 6 | 6 | | WC | L Siegemund | 4 | 6 | 3 | | | | | | | | | |
| WC | C Vandeweghe | 6 | 6 | | WC | C Vandeweghe | 6 | 4 | 6 | | | | | | | | | |
| 7 | S Stephens | 1 | 0 | | | | | | | | | | | | WC | C Vandeweghe | 6 | 6 |
| | | | | | | | | | | | | | | | 6 | C Garcia | 4 | 2 |
| | | | | | 3 | E Svitolina | 2 | 6 | 3 | | | | | | | | | |
| | J Görges | 2 | 2 | | Q | M Vondroušová | 6 | 1 | 2$^r$ | | | | | | | | | |
| Q | M Vondroušová | 6 | 6 | | | | | | | 3 | E Svitolina | 7$^7$ | 4 | 2 | | | | |
| Q | M Kostyuk | 6 | 6 | | | | | | | 6 | C Garcia | 6$^4$ | 6 | 6 | | | | |
| WC | A Lottner | 4 | 1 | | Q | M Kostyuk | 1 | 6 | 5 | | | | | | | | | |
| WC | M Sharapova | 6 | 6$^6$ | 4 | 6 | C Garcia | 6 | 3 | 7 | | | | | | | | | |
| 6 | C Garcia | 3 | 7$^8$ | 6 | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 5 | Ka Plíšková | 6 | 6 | | | | | | | | | | | | | | |
| | K Bertens | 2 | 2 | | 5 | Ka Plíšková | 7$^7$ | 6 | | | | | | | | | |
| Q | V Kudermetova | 7$^7$ | 6 | | Q | V Kudermetova | 6$^4$ | 3 | | | | | | | | | |
| | C Suárez Navarro | 6$^5$ | 2 | | | | | | 5 | Ka Plíšková | 5 | 7 | 6 | | | | |
| LL | C Witthöft | 3 | 2 | | | | | | 4 | J Ostapenko | 7 | 5 | 4 | | | | |
| Q | Z Diyas | 6 | 6 | | Q | Z Diyas | 3 | 0 | | | | | | | | | |
| | | | | | 4 | J Ostapenko | 6 | 6 | | | | | | | | | |
| | | | | | | | | | | | | | | 5 | Ka Plíšková | 6 | 6 |
| 8 | P Kvitová | 3 | 2 | | | | | | | | | | | | A Kontaveit | 4 | 2 |
| | A Kerber | 6 | 6 | | | A Kerber | 0 | 0$^r$ | | | | | | | | | |
| | K Mladenovic | 7 | 6$^3$ | 6$^5$ | | A Kontaveit | 6 | 2 | | | | | | | | | |
| | A Kontaveit | 5 | 7$^7$ | 7$^7$ | | | | | | A Kontaveit | 7 | 6$^6$ | 6 | | | | |
| | M Keys | 6$^7$ | 7 | 4 | | | | | | A Pavlyuchenkova | 5 | 7$^8$ | 4 | | | | |
| | A Pavlyuchenkova | 7$^9$ | 5 | 6 | | A Pavlyuchenkova | 7 | 0 | | | | | | | | | |
| | | | | | 2 | G Muguruza | 5 | 0$^r$ | | | | | | | | | |

## Qualifying
### Seeds

* Alizé Cornet (qualifying competition)
* Zarina Diyas (qualified)
* Carina Witthöft (qualifying competition, lucky loser)
* Hsieh Su-wei (second round)
* Kaia Kanepi (qualifying competition)
* Markéta Vondroušová (qualified)
* Varvara Lepchenko (qualifying competition)
* Bernarda Pera (first round)

### Qualifiers

* Marta Kostyuk
* Zarina Diyas
* Markéta Vondroušová
* Veronika Kudermetova

### Lucky loser

* Carina Witthöft

### Draw
#### First qualifier

| First round | First round | First round | First round | Second round | Second round | Second round | Second round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 1 | Alizé Cornet | 6 | 6 | | | | | | | | | |
| | Daniela Seguel | 1 | 3 | | | | | | | | | |
| | Daniela Seguel | 1 | 3 | 1 | Alizé Cornet | 7$^7$ | 7$^7$ | | | | | |
| | | | | | Conny Perrin | 6$^2$ | 6$^2$ | | | | | |
| | Conny Perrin | 6 | 7$^7$ | | Conny Perrin | 6$^2$ | 6$^2$ | | | | | |
| | Tamara Korpatsch | 1 | 6$^4$ | | | | | | | | | |
| | Tamara Korpatsch | 1 | 6$^4$ | | | | | 1 | Alizé Cornet | 6 | 2 | 3 |
| | | | | | | | | | Marta Kostyuk | 4 | 6 | 6 |
| WC | Julia Middendorf | 1 | 2 | | | | | | | | | | Marta Kostyuk | 4 | 6 | 6 |
| | Marta Kostyuk | 6 | 6 | | | | | | | | | |
| | Marta Kostyuk | 6 | 6 | | Marta Kostyuk | 7 | 2 | | | | | |
| | | | | | Alexandra Cadanțu | 5 | 0$^r$ | | | | | |
| | Alexandra Cadanțu | 6 | 7 | | Alexandra Cadanțu | 5 | 0$^r$ | | | | | |
| 8 | Bernarda Pera | 4 | 5 | | | | | | | | | |

#### Second qualifier

| First round | First round | First round | First round | Second round | Second round | Second round | Second round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 2 | Zarina Diyas | 6 | 6 | | | | | | | | | |
| | Marie Bouzková | 4 | 2 | | | | | | | | | |
| | Marie Bouzková | 4 | 2 | 2 | Zarina Diyas | 6 | 6 | | | | | |
| | | | | WC | Anna Gabric | 3 | 1 | | | | | |
| | Fanny Stollár | 5 | 6$^4$ | WC | Anna Gabric | 3 | 1 | | | | | |
| WC | Anna Gabric | 7 | 7$^7$ | | | | | | | | | |
| WC | Anna Gabric | 7 | 7$^7$ | | | | | 2 | Zarina Diyas | 6 | 4 | 6 |
| | | | | | | | | 5 | Kaia Kanepi | 4 | 6 | 4 |
| | Dayana Yastremska | 6 | 6 | | | | | | | | | | 5 | Kaia Kanepi | 4 | 6 | 4 |
| | Marina Melnikova | 3 | 3 | | | | | | | | | |
| | Marina Melnikova | 3 | 3 | | Dayana Yastremska | 2 | 4 | | | | | |
| | | | | 5 | Kaia Kanepi | 6 | 6 | | | | | |
| | Chloé Paquet | 2 | 1 | 5 | Kaia Kanepi | 6 | 6 | | | | | |
| 5 | Kaia Kanepi | 6 | 6 | | | | | | | | | |

#### Third qualifier

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 3 | Carina Witthöft | 6 | 6 | | | | | | | | | | | |
| | Michaela Hončová | 0 | 1 | | | | | | | | | | | |
| | Michaela Hončová | 0 | 1 | | 3 | Carina Witthöft | 2 | 6 | 6 | | | | | |
| | | | | | | Anna Zaja | 6 | 0 | 3 | | | | | |
| | Anna Zaja | 6 | 6 | | | Anna Zaja | 6 | 0 | 3 | | | | | |
| | Katharina Hobgarski | 4 | 4 | | | | | | | | | | | |
| | Katharina Hobgarski | 4 | 4 | | | | | | | 3 | Carina Witthöft | 7 | 1 | 3 |
| | | | | | | | | | | 6 | Markéta Vondroušová | 5 | 6 | 6 |
| | Fiona Ferro | 5 | 1 | | | | | | | | | | | | 6 | Markéta Vondroušová | 5 | 6 | 6 |
| | Océane Dodin | 7 | 6 | | | | | | | | | | | |
| | Océane Dodin | 7 | 6 | | | Océane Dodin | 3 | 6 | 1 | | | | | |
| | | | | | 6 | Markéta Vondroušová | 6 | 1 | 6 | | | | | |
| | Karolína Muchová | 6$^5$ | 6 | 2 | 6 | Markéta Vondroušová | 6 | 1 | 6 | | | | | |
| 6 | Markéta Vondroušová | 7$^7$ | 4 | 6 | | | | | | | | | | |

#### Fourth qualifier

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 4 | Hsieh Su-wei | 2 | 7 | 6 | | | | | | | | |
| WC | Katharina Gerlach | 6 | 5 | 2 | | | | | | | | |
| WC | Katharina Gerlach | 6 | 5 | 2 | 4 | Hsieh Su-wei | 3 | 3 | | | | |
| | | | | | | Veronika Kudermetova | 6 | 6 | | | | |
| | Petra Krejsová | 2 | 3 | | | Veronika Kudermetova | 6 | 6 | | | | |
| | Veronika Kudermetova | 6 | 6 | | | | | | | | | |
| | Veronika Kudermetova | 6 | 6 | | | | | | | Veronika Kudermetova | 6 | 6 |
| | | | | | | | | | 7 | Varvara Lepchenko | 2 | 4 |
| WC | Lena Rüffer | 4 | 6 | 6 | | | | | | | | | 7 | Varvara Lepchenko | 2 | 4 |
| | Paula Badosa Gibert | 6 | 3 | 0 | | | | | | | | |
| | Paula Badosa Gibert | 6 | 3 | 0 | WC | Lena Rüffer | 4 | 1 | | | | |
| | | | | | 7 | Varvara Lepchenko | 6 | 6 | | | | |
| | Magdalena Fręch | 2 | 6$^1$ | | 7 | Varvara Lepchenko | 6 | 6 | | | | |
| 7 | Varvara Lepchenko | 6 | 7$^7$ | | | | | | | | | |