# 2021 Thoreau Tennis Open – Singles

Caroline Dolehide was the defending champion, having won the previous edition in 2019. She lost in the second round to Katrina Scott.
Magdalena Fręch won the title, defeating Renata Zarazúa in the final, 6–3, 7–6$^{(7–4)}$.

## Seeds

* Alison Van Uytvanck (withdrew)
* Hsieh Su-wei (quarterfinals)
* Madison Brengle (semifinals)
* Vera Zvonareva (semifinals)
* Lauren Davis (first round)
* Christina McHale (first round)
* Greet Minnen (second round)
* Renata Zarazúa (final)
* Storm Sanders (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

| Semifinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final |
| | Magdalena Fręch | 7 | 6 | | | | | |
| 4 | Vera Zvonareva | 5 | 3 | | | | | |
| 4 | Vera Zvonareva | 5 | 3 | | | Magdalena Fręch | 6 | 7$^7$ |
| | | | | | 8 | Renata Zarazúa | 3 | 6$^4$ |
| 3 | Madison Brengle | 6 | 4 | 2 | 8 | Renata Zarazúa | 3 | 6$^4$ |
| 8 | Renata Zarazúa | 2 | 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 | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 9 | S Sanders | 6 | 6 | | | | | | | | | | | | | | | |
| WC | A Parks | 2 | 4 | | 9 | S Sanders | 3 | 2 | | | | | | | | | | |
| PR | R Marino | 3 | 6$^4$ | | | M Fręch | 6 | 6 | | | | | | | | | | |
| | M Fręch | 6 | 7$^7$ | | | | | | | | M Fręch | 6 | 4 | 7 | | | | |
| | C Dolehide | 6 | 6 | | | | | | | WC | K Scott | 4 | 6 | 5 | | | | |
| Q | R Anderson | 3 | 4 | | | C Dolehide | 6 | 0 | 5 | | | | | | | | | |
| WC | K Scott | 7$^7$ | 7 | | WC | K Scott | 1 | 6 | 7 | | | | | | | | | |
| 5 | L Davis | 6$^1$ | 5 | | | | | | | | | | | | | M Fręch | 7 | 6 |
| 4 | V Zvonareva | 6 | 6 | | | | | | | | | | | | 4 | V Zvonareva | 5 | 3 |
| Q | E-s Liang | 1 | 2 | | 4 | V Zvonareva | 6 | 6 | | | | | | | | | | |
| | T Maria | 0 | 3 | | | V Lepchenko | 3 | 4 | | | | | | | | | | |
| | V Lepchenko | 6 | 6 | | | | | | | 4 | V Zvonareva | 5 | 6 | 6 | | | | |
| Q | M Bolkvadze | 6 | 3 | 6 | | | | | | Q | M Bolkvadze | 7 | 2 | 4 | | | | |
| Q | V Duval | 2 | 6 | 1 | Q | M Bolkvadze | 6 | 6 | | | | | | | | | | |
| | L Küng | 4 | 1 | | 7 | G Minnen | 4 | 4 | | | | | | | | | | |
| 7 | G Minnen | 6 | 6 | | | | | | | | | | | | | | | |

### Bottom 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 | Semifinals |
| 6 | C McHale | 4 | 3 | | | | | | | | | | | | | | | | |
| | C Bucșa | 6 | 6 | | | C Bucșa | 6 | 6 | | | | | | | | | | | |
| | UM Arconada | 7$^{13}$ | 2 | 6 | | UM Arconada | 3 | 3 | | | | | | | | | | | |
| | J Loeb | 6$^{11}$ | 6 | 4 | | | | | | | C Bucșa | 3 | 5 | | | | | | |
| WC | L Sun | 6 | 6 | | | | | | | 3 | M Brengle | 6 | 7 | | | | | | |
| | K Nara | 1 | 3 | | WC | L Sun | 1 | 7$^7$ | 2 | | | | | | | | | | |
| | M Inglis | 3 | 0$^r$ | | 3 | M Brengle | 6 | 6$^5$ | 6 | | | | | | | | | | |
| 3 | M Brengle | 6 | 3 | | | | | | | | | | | | 3 | M Brengle | 6 | 4 | 2 |
| 8 | R Zarazúa | 6$^5$ | 6 | 6 | | | | | | | | | | | 8 | R Zarazúa | 2 | 6 | 6 |
| LL | A Glatch | 7$^7$ | 2 | 3 | 8 | R Zarazúa | 6 | 6 | | | | | | | | | | | |
| WC | S Whittle | 6$^3$ | 1 | | | G Min | 1 | 3 | | | | | | | | | | | |
| | G Min | 7$^7$ | 6 | | | | | | | 8 | R Zarazúa | 6 | 2 | 7 | | | | | |
| | L Cabrera | 4 | 6 | 4 | | | | | | 2 | S-w Hsieh | 3 | 6 | 5 | | | | | |
| | B Haddad Maia | 6 | 3 | 6 | | B Haddad Maia | 3 | 1 | | | | | | | | | | | |
| | A Raina | 2 | 2 | | 2 | S-w Hsieh | 6 | 6 | | | | | | | | | | | |
| 2 | S-w Hsieh | 6 | 6 | | | | | | | | | | | | | | | | |

## Qualifying
### Seeds

* Mariam Bolkvadze (qualified)
* Beatriz Haddad Maia (moved to main draw)
* Kateryna Bondarenko (first round)
* Robin Anderson (qualified)
* Mona Barthel (first round)
* Whitney Osuigwe (first round)
* Samantha Murray Sharan (qualifying competition)
* Liang En-shuo (qualified)

### Qualifiers

* Mariam Bolkvadze
* Victoria Duval
* Liang En-shuo
* Robin Anderson

### Lucky loser

* Alexa Glatch

### Qualifying draw
#### First qualifier

| First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 1 | Mariam Bolkvadze | 6 | 6 | | | | |
| PR | Peangtarn Plipuech | 2 | 4 | | | | |
| PR | Peangtarn Plipuech | 2 | 4 | 1 | Mariam Bolkvadze | 6 | 6 |
| | | | | | Sophie Chang | 2 | 1 |
| | Sophie Chang | 6 | 6 | | Sophie Chang | 2 | 1 |
| 5 | Mona Barthel | 2 | 3 | | | | |

#### Second qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| Alt | Eden Silva | 2 | 6 | 1 | | | | |
| | Victoria Duval | 6 | 4 | 6 | | | | |
| | Victoria Duval | 6 | 4 | 6 | | Victoria Duval | 7 | 6 |
| | | | | | 7/PR | Samantha Murray Sharan | 5 | 4 |
| WC | Brittany Collens | 5 | 0 | | 7/PR | Samantha Murray Sharan | 5 | 4 |
| 7/PR | Samantha Murray Sharan | 7 | 6 | | | | | |

#### Third qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 3 | Kateryna Bondarenko | 7 | 4 | 5 | | | | | |
| | Alexa Glatch | 5 | 6 | 7 | | | | | |
| | Alexa Glatch | 5 | 6 | 7 | | Alexa Glatch | 6 | 2 | 3 |
| | | | | | 8/PR | Liang En-shuo | 3 | 6 | 6 |
| | Hsu Chieh-yu | 1 | 6 | 2 | 8/PR | Liang En-shuo | 3 | 6 | 6 |
| 8/PR | Liang En-shuo | 6 | 4 | 6 | | | | | |

#### Fourth qualifier

| First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 4 | Robin Anderson | 7 | 6 | | | | |
| | Catherine Harrison | 5 | 1 | | | | |
| | Catherine Harrison | 5 | 1 | 4 | Robin Anderson | 6 | 6 |
| | | | | WC | Victoria Hu | 4 | 3 |
| WC | Victoria Hu | 6 | 6 | WC | Victoria Hu | 4 | 3 |
| 6 | Whitney Osuigwe | 4 | 2 | | | | |