# 2021 Berkeley Tennis Club Challenge – Singles

Madison Brengle was the defending champion but chose to compete at the 2021 Chicago Fall Tennis Classic instead.
Usue Maitane Arconada won the title, defeating Marcela Zacarías in the final, 6–1, 6–3.

## Seeds

* Zheng Saisai (first round)
* Wang Xinyu (first round)
* Panna Udvardy (first round)
* Kurumi Nara (semifinals, retired)
* Katie Volynets (first round)
* Francesca Di Lorenzo (first round)
* Mayo Hibi (semifinals)
* Liang En-shuo (quarterfinals)

## 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 |
| | Marcela Zacarías | 5 | 3 | | | | |
| 4 | Kurumi Nara | 7 | 0$^r$ | | | | |
| 4 | Kurumi Nara | 7 | 0$^r$ | | Marcela Zacarías | 1 | 3 |
| | | | | | Usue Maitane Arconada | 6 | 6 |
| 7 | Mayo Hibi | 3 | 7$^7$ | 4 | Usue Maitane Arconada | 6 | 6 |
| | Usue Maitane Arconada | 6 | 6$^3$ | 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 |
| 1 | S Zheng | 6 | 5 | 1 | | | | | | | | | | | | | | |
| Q | M Kozyreva | 4 | 7 | 6 | Q | M Kozyreva | 5 | 3 | | | | | | | | | | |
| | K Okamura | 5 | 2 | | Q | E Navarro | 7 | 6 | | | | | | | | | | |
| Q | E Navarro | 7 | 6 | | | | | | | Q | E Navarro | 5 | 7 | 2 | | | | |
| WC | R Brantmeier | 6 | 2 | 6 | | | | | | | M Zacarías | 7 | 5 | 6 | | | | |
| Q | A Bozovic | 3 | 6 | 4 | WC | R Brantmeier | 7 | 2 | 1 | | | | | | | | | |
| | M Zacarías | 7$^7$ | 3 | 6 | | M Zacarías | 5 | 6 | 6 | | | | | | | | | |
| 5 | K Volynets | 6$^5$ | 6 | 2 | | | | | | | | | | | | M Zacarías | 5 | 3 |
| 4 | K Nara | 7$^7$ | 7 | | | | | | | | | | | | 4 | K Nara | 7 | 0$^r$ |
| Q | H Kuwata | 6$^1$ | 5 | | 4 | K Nara | 6 | 6 | | | | | | | | | | |
| Q | M Manasse | 6$^3$ | 2 | | WC | E Douglas | 3 | 2 | | | | | | | | | | |
| WC | E Douglas | 7$^7$ | 6 | | | | | | | 4 | K Nara | 7$^7$ | 5 | 6 | | | | |
| | D Lao | 2 | 0$^r$ | | | | | | | Q | S Chang | 6$^5$ | 7 | 4 | | | | |
| Q | S Chang | 6 | 1 | | Q | S Chang | 6 | 6 | | | | | | | | | | |
| | D Jakupović | 6 | 6 | | | D Jakupović | 1 | 2 | | | | | | | | | | |
| 6 | F Di Lorenzo | 3 | 2 | | | | | | | | | | | | | | | |

### 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 | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 7 | M Hibi | 6 | 6 | | | | | | | | | | | | | | | |
| Q | J Hart | 3 | 2 | | 7 | M Hibi | 6 | 7$^7$ | | | | | | | | | | |
| WC | V Duval | 6 | 6 | | WC | V Duval | 0 | 6$^3$ | | | | | | | | | | |
| Q | H Kaji | 2 | 1 | | | | | | | 7 | M Hibi | 6 | 6 | | | | | |
| WC | P Expósito Díaz Delgado | 2 | 6 | 1 | | | | | | PR | L Chirico | 2 | 3 | | | | | |
| SE | K Day | 6 | 3 | 6 | SE | K Day | 0$^r$ | | | | | | | | | | | |
| PR | L Chirico | 6 | 4 | 6 | PR | L Chirico | 2 | | | | | | | | | | | |
| 3 | P Udvardy | 4 | 6 | 4 | | | | | | | | | | 7 | M Hibi | 3 | 7$^7$ | 4 |
| 8 | E-s Liang | 6 | 7 | | | | | | | | | | | | UM Arconada | 6 | 6$^3$ | 6 |
| | Jia Lu | 4 | 5 | | 8 | E-s Liang | 6 | 6 | | | | | | | | | | |
| | H Chang | 6 | 4 | 6 | | H Chang | 2 | 1 | | | | | | | | | | |
| | M Björklund | 3 | 6 | 1 | | | | | | 8 | E-s Liang | 3 | 1 | | | | | |
| | K Sebov | 6$^7$ | 4 | | | | | | | | UM Arconada | 6 | 6 | | | | | |
| | UM Arconada | 7$^9$ | 6 | | | UM Arconada | 6 | 6$^5$ | 6 | | | | | | | | | |
| | S Vickery | 7 | 7$^7$ | | | S Vickery | 4 | 7$^7$ | 2 | | | | | | | | | |
| 2 | Xin Wang | 5 | 6$^5$ | | | | | | | | | | | | | | | |