# 2021 Monterrey Open – Singles

Leylah Fernandez defeated Viktorija Golubic in the final, 6–1, 6–4 to win the singles tennis title at the 2021 Monterrey Open. Fernandez did not drop a set en route to her first WTA Tour singles title.
Elina Svitolina was the reigning champion, but decided not to participate.

## Seeds

* Sloane Stephens (first round)
* Nadia Podoroska (first round)
* Zheng Saisai (quarterfinals)
* Marie Bouzková (withdrew)
* Heather Watson (first round)
* Anna Blinkova (first round)
* Sara Sorribes Tormo (semifinals)
* Ann Li (semifinals)
* Nao Hibino (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 |
| | Leylah Fernandez | 7 | 7 | | | | |
| 7 | Sara Sorribes Tormo | 5 | 5 | | | | |
| 7 | Sara Sorribes Tormo | 5 | 5 | | Leylah Fernandez | 6 | 6 |
| | | | | Q | Viktorija Golubic | 1 | 4 |
| 8 | Ann Li | 2 | 4 | Q | Viktorija Golubic | 1 | 4 |
| Q | Viktorija Golubic | 6 | 6 | | | | |

### 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 | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | S Stephens | 2 | 2 | | | | | | | | | | | | | | |
| LL | K Kučová | 6 | 6 | | LL | K Kučová | 1 | 4 | | | | | | | | | |
| WC | C Vandeweghe | 3 | 2 | | | LA Fernandez | 6 | 6 | | | | | | | | | |
| | LA Fernandez | 6 | 6 | | | | | | | | LA Fernandez | 7 | 6 | | | | |
| WC | C Dolehide | 3 | 1 | | | | | | | | V Kužmová | 5 | 3 | | | | |
| | V Kužmová | 6 | 6 | | | V Kužmová | 6 | 6 | | | | | | | | | |
| LL | H Dart | 6 | 7$^7$ | | LL | H Dart | 4 | 3 | | | | | | | | | |
| 5 | H Watson | 4 | 6$^1$ | | | | | | | | | | | | LA Fernandez | 7 | 7 |
| 9 | N Hibino | 6 | 2 | 3 | | | | | | | | | | 7 | S Sorribes Tormo | 5 | 5 |
| | J Paolini | 3 | 6 | 6 | | J Paolini | 6 | 2 | 2 | | | | | | | | |
| PR | AK Schmiedlová | 6 | 6 | | PR | AK Schmiedlová | 2 | 6 | 6 | | | | | | | | |
| PR | K Boulter | 4 | 0 | | | | | | | PR | AK Schmiedlová | 3 | 5 | | | | |
| Q | K Juvan | 6 | 6 | | | | | | | 7 | S Sorribes Tormo | 6 | 7 | | | | |
| Q | C Osorio | 4 | 4 | | Q | K Juvan | | | | | | | | | | | |
| Q | L Tsurenko | 7 | 2 | 4 | 7 | S Sorribes Tormo | w/o | | | | | | | | | | |
| 7 | S Sorribes Tormo | 5 | 6 | 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 | Semifinals | Semifinals | Semifinals | Semifinals |
| 8 | A Li | 6 | 7 | | | | | | | | | | | | | |
| | A Rus | 3 | 5 | | 8 | A Li | 6 | 6 | | | | | | | | |
| WC | R Zarazúa | 6$^8$ | 3 | | | T Zidanšek | 4 | 3 | | | | | | | | |
| | T Zidanšek | 7$^{10}$ | 6 | | | | | | 8 | A Li | 7 | 6 | | | | |
| | L Zhu | 7 | 7$^7$ | | | | | | 3 | S Zheng | 5 | 1 | | | | |
| SE | E Bouchard | 5 | 6$^3$ | | | L Zhu | 1 | 2 | | | | | | | | |
| | V Gracheva | 3 | 5 | | 3 | S Zheng | 6 | 6 | | | | | | | | |
| 3 | S Zheng | 6 | 7 | | | | | | | | | | 8 | A Li | 2 | 4 |
| 6 | A Blinkova | 4 | 4 | | | | | | | | | | Q | V Golubic | 6 | 6 |
| Q | V Golubic | 6 | 6 | | Q | V Golubic | 6 | 6 | | | | | | | | |
| Q | M Sherif | 6 | 2 | 3 | | L Davis | 3 | 1 | | | | | | | | |
| | L Davis | 1 | 6 | 6 | | | | | Q | V Golubic | 6 | 6 | | | | |
| | M Trevisan | 3 | 2 | | | | | | Q | A Kalinskaya | 2 | 4 | | | | |
| | N Stojanović | 6 | 6 | | | N Stojanović | 4 | 3 | | | | | | | | |
| Q | A Kalinskaya | 6 | 6 | | Q | A Kalinskaya | 6 | 6 | | | | | | | | |
| 2 | N Podoroska | 4 | 4 | | | | | | | | | | | | | |

## Qualifying
### Seeds

* Kaja Juvan (qualified)
* Viktorija Golubic (qualified)
* Aliona Bolsova (first round)
* Sara Errani (first round)
* Greet Minnen (withdrew)
* Kristie Ahn (first round)
* Mayar Sherif (qualified)
* Anna-Lena Friedsam (first round)
* Katarzyna Kawa (first round)
* Anna Kalinskaya (qualified)
* Wang Xiyu (first round)
* Irina Bara (first round)

### Qualifiers

* Kaja Juvan
* Viktorija Golubic
* Lesia Tsurenko
* Camila Osorio
* Anna Kalinskaya
* Mayar Sherif

### Lucky losers

* Kristína Kučová
* Harriet Dart

### Qualifying draw
#### First qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 1 | Kaja Juvan | 6 | 4 | 6 | | | | |
| | Olga Govortsova | 2 | 6 | 2 | | | | |
| | Olga Govortsova | 2 | 6 | 2 | 1 | Kaja Juvan | 6 | 6 |
| | | | | | Alt | Kurumi Nara | 1 | 1 |
| Alt | Kurumi Nara | 6 | 6 | | Alt | Kurumi Nara | 1 | 1 |
| 12 | Irina Bara | 1 | 0 | | | | | |

#### Second qualifier

| First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 2 | Viktorija Golubic | 6 | 6 | | | | |
| WC | Ana Sofía Sánchez | 0 | 1 | | | | |
| WC | Ana Sofía Sánchez | 0 | 1 | 2 | Viktorija Golubic | 6 | 7$^7$ |
| | | | | | Leonie Küng | 3 | 6$^3$ |
| | Leonie Küng | 6 | 6 | | Leonie Küng | 3 | 6$^3$ |
| 8 | Anna-Lena Friedsam | 1 | 2 | | | | |

#### Third qualifier

| First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition |
| 3 | Aliona Bolsova | 3 | 5 | | | |
| | Kristína Kučová | 6 | 7 | | | |
| | Kristína Kučová | 6 | 7 | Kristína Kučová | 3 | 2 |
| | | | | Lesia Tsurenko | 6 | 6 |
| | Lesia Tsurenko | 6 | 6 | Lesia Tsurenko | 6 | 6 |
| 9 | Katarzyna Kawa | 4 | 3 | | | |

#### Fourth qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 4 | Sara Errani | 0 | 2 | | | | | |
| | Harriet Dart | 6 | 6 | | | | | |
| | Harriet Dart | 6 | 6 | | | Harriet Dart | 4 | 5 |
| | | | | | WC | Camila Osorio | 6 | 7 |
| WC | Camila Osorio | 7$^7$ | 4 | 6 | WC | Camila Osorio | 6 | 7 |
| 11 | Wang Xiyu | 6$^2$ | 6 | 2 | | | | |

#### Fifth qualifier

| First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| Alt | Lara Arruabarrena | 6 | 6 | | | | |
| | Elisabetta Cocciaretto | 2 | 4 | | | | |
| | Elisabetta Cocciaretto | 2 | 4 | Alt | Lara Arruabarrena | 4 | 3 |
| | | | | 10 | Anna Kalinskaya | 6 | 6 |
| WC | Fernanda Contreras | 2 | 1 | 10 | Anna Kalinskaya | 6 | 6 |
| 10 | Anna Kalinskaya | 6 | 6 | | | | |

#### Sixth qualifier

| First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 6 | Kristie Ahn | 4 | 6$^5$ | | | | |
| | Usue Maitane Arconada | 6 | 7$^7$ | | | | |
| | Usue Maitane Arconada | 6 | 7$^7$ | | Usue Maitane Arconada | 3 | 4 |
| | | | | 7 | Mayar Sherif | 6 | 6 |
| WC | Marcela Zacarías | 3 | 6$^0$ | 7 | Mayar Sherif | 6 | 6 |
| 7 | Mayar Sherif | 6 | 7$^7$ | | | | |