# 2021 Oeiras Ladies Open – Singles

This was the first edition of the tournament.
Polona Hercog won the title after Clara Burel withdrew before the final.

## Seeds

All seeds receive a bye into the second round.
* Polona Hercog (champion)
* Greet Minnen (third round)
* Anhelina Kalinina (semifinals)
* Çağla Büyükakçay (withdrew)
* Clara Burel (final, withdrew)
* Mandy Minella (second round)
* Chloé Paquet (second round)
* Georgina García Pérez (semifinals)
* Mariam Bolkvadze (second round)
* Rebecca Šramková (third round)
* Daria Snigur (third round)
* Natalija Kostić (third round)
* Francesca Jones (quarterfinals)
* Martina Di Giuseppe (second round)
* Marina Melnikova (second round)
* Lu Jiajing (second 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

| Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final |
| 1 | Polona Hercog | 6 | 6 | | | | | | | | | |
| SE | Lucia Bronzetti | 3 | 2 | | | | | | | | | |
| SE | Lucia Bronzetti | 3 | 2 | | 1 | Polona Hercog | 6 | 3 | 6 | | | |
| | | | | | 3 | Anhelina Kalinina | 3 | 6 | 3 | | | |
| 3 | Anhelina Kalinina | 6 | 6 | | 3 | Anhelina Kalinina | 3 | 6 | 3 | | | |
| | Eva Guerrero Álvarez | 1 | 2 | | | | | | | | | |
| | Eva Guerrero Álvarez | 1 | 2 | | | | | | | 1 | Polona Hercog | w/o |
| | | | | | | | | | | 5 | Clara Burel | |
| 5 | Clara Burel | 5 | 6 | 6 | | | | | | | | | 5 | Clara Burel |
| 13 | Francesca Jones | 7 | 4 | 2 | | | | | | | | |
| 13 | Francesca Jones | 7 | 4 | 2 | 5 | Clara Burel | 4 | 6 | 6 | | | |
| | | | | | 8 | Georgina García Pérez | 6 | 4 | 1 | | | |
| 8 | Georgina García Pérez | 6 | 6 | | 8 | Georgina García Pérez | 6 | 4 | 1 | | | |
| | Despina Papamichail | 4 | 1 | | | | | | | | | |

### Top half
#### Section 1

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Third round | Third round | Third round | Third round | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | 1 | P Hercog | w/o | | | | | | | | | | | |
| | N-l Han | 2 | 3 | | | E Gorgodze | | | | | | | | | | | | |
| | E Gorgodze | 6 | 6 | | | | | | | 1 | P Hercog | 6 | 1 | 6 | | | | |
| PR | A Dulgheru | 7$^7$ | 1 | 6 | | | | | | PR | A Dulgheru | 4 | 6 | 4 | | | | |
| | P Özgen | 6$^3$ | 6 | 2 | PR | A Dulgheru | 6 | 2 | 6 | | | | | | | | | |
| | | | | | 15 | M Melnikova | 3 | 6 | 3 | | | | | | | | | |
| | | | | | | | | | | | | | | | 1 | P Hercog | 6 | 6 |
| | | | | | | | | | | | | | | | SE | L Bronzetti | 3 | 2 |
| | | | | | 11 | D Snigur | 5 | 6 | 6 | | | | | | | | | |
| | R Hogenkamp | 1 | 6 | 2 | WC | F Jorge | 7 | 4 | 1 | | | | | | | | | |
| WC | F Jorge | 6 | 3 | 6 | | | | | | 11 | D Snigur | 2 | 2 | | | | | |
| SE | L Bronzetti | 7 | 7 | | | | | | | SE | L Bronzetti | 6 | 6 | | | | | |
| Q | S-j Jang | 5 | 5 | | SE | L Bronzetti | 6 | 6 | | | | | | | | | | |
| | | | | | 6 | M Minella | 3 | 4 | | | | | | | | | | |

#### Section 2

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Third round | Third round | Third round | Third round | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | 3 | A Kalinina | 6 | 6 | | | | | | | | | | |
| Q | D Parry | 5 | 1 | | Q | O Sáez Larra | 3 | 1 | | | | | | | | | | |
| Q | O Sáez Larra | 7 | 6 | | | | | | | 3 | A Kalinina | 6 | 4 | 6 | | | | |
| Q | S Lamens | 2 | 6 | 6 | | | | | | Q | S Lamens | 2 | 6 | 4 | | | | |
| WC | B Haddad Maia | 6 | 4 | 3 | Q | S Lamens | 2 | 6 | 6 | | | | | | | | | |
| | | | | | 16 | Jia Lu | 6 | 3 | 4 | | | | | | | | | |
| | | | | | | | | | | | | | | | 3 | A Kalinina | 6 | 6 |
| | | | | | | | | | | | | | | | | E Guerrero Álvarez | 1 | 2 |
| | | | | | 12 | N Kostić | 6 | 1 | 7$^{14}$ | | | | | | | | | |
| | I Burillo Escorihuela | 6 | 6 | | | I Burillo Escorihuela | 1 | 6 | 6$^{12}$ | | | | | | | | | |
| Q | S Wagner | 4 | 1 | | | | | | | 12 | N Kostić | 4 | 1 | | | | | |
| | E Guerrero Álvarez | 1 | 7 | 6 | | | | | | | E Guerrero Álvarez | 6 | 6 | | | | | |
| | T Mrdeža | 6 | 5 | 4 | | E Guerrero Álvarez | 5 | 6 | 6 | | | | | | | | | |
| | | | | | 7 | C Paquet | 7 | 1 | 4 | | | | | | | | | |

### Bottom half
#### Section 3

| First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Third round | Third round | Third round | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | 5 | C Burel | 6 | 6 | | | | | | | | | | |
| | C Perrin | 6 | 6 | | C Perrin | 1 | 0 | | | | | | | | | | |
| | T Lukas | 0 | 4 | | | | | | 5 | C Burel | 7 | 7$^7$ | | | | | |
| | V Kan | 4 | 2 | | | | | | | J Niemeier | 5 | 6$^3$ | | | | | |
| | J Niemeier | 6 | 6 | | J Niemeier | 6 | 4 | 6 | | | | | | | | | |
| | | | | 9 | M Bolkvadze | 0 | 6 | 4 | | | | | | | | | |
| | | | | | | | | | | | | | 5 | C Burel | 5 | 6 | 6 |
| | | | | | | | | | | | | | 13 | F Jones | 7 | 4 | 2 |
| | | | | 13 | F Jones | 6 | 4 | 6 | | | | | | | | | |
| Q | F Di Sarra | 1 | 2 | | V Grammatikopoulou | 3 | 6 | 3 | | | | | | | | | |
| | V Grammatikopoulou | 6 | 6 | | | | | | 13 | F Jones | 6 | 6 | | | | | |
| | I Shinikova | 6$^4$ | 2 | | | | | | LL | M Bassols Ribera | 3 | 3 | | | | | |
| Q | K Volynets | 7$^7$ | 6 | Q | K Volynets | 3 | 6$^4$ | | | | | | | | | | |
| | | | | LL | M Bassols Ribera | 6 | 7$^7$ | | | | | | | | | | |

#### Section 4

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Third round | Third round | Third round | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | 8 | G García Pérez | 7$^8$ | 1 | 6 | | | | | | | | |
| | M Zanevska | 6 | 6 | | | M Zanevska | 6$^6$ | 6 | 4 | | | | | | | | |
| WC | I Murta | 0 | 0 | | | | | | | 8 | G García Pérez | 6 | 6 | | | | |
| WC | AF Santos | 6$^1$ | 3 | | | | | | | 10 | R Šramková | 2 | 4 | | | | |
| WC | E Hamaliy | 7$^7$ | 6 | | WC | E Hamaliy | 1 | 0 | | | | | | | | | |
| | | | | | 10 | R Šramková | 6 | 6 | | | | | | | | | |
| | | | | | | | | | | | | | | 8 | G García Pérez | 6 | 6 |
| | | | | | | | | | | | | | | | D Papamichail | 4 | 1 |
| | | | | | 14 | M Di Giuseppe | 1 | 4 | | | | | | | | | |
| Q | S Herrmann | 2 | 6 | 6$^6$ | | D Papamichail | 6 | 6 | | | | | | | | | |
| | D Papamichail | 6 | 1 | 7$^8$ | | | | | | | D Papamichail | 6 | 6 | | | | |
| JE | V Jiménez Kasintseva | 6 | 2 | 0 | | | | | | 2 | G Minnen | 4 | 0 | | | | |
| | RL Jani | 4 | 6 | 6 | | RL Jani | 4 | 5 | | | | | | | | | |
| | | | | | 2 | G Minnen | 6 | 7 | | | | | | | | | |