# 2021 Mercer Tennis Classic – Singles

Catherine Bellis was the defending champion but chose not to participate.
Madison Brengle won the title, defeating Zarina Diyas in the final, 6–4, 4–6, 6–4.

## Seeds

* Madison Brengle (champion)
* Zarina Diyas (final)
* Kristína Kučová (first round, retired)
* Beatriz Haddad Maia (semifinals)
* Renata Zarazúa (quarterfinals, retired)
* Maddison Inglis (first round)
* Wang Xiyu (semifinals)
* Rebecca Marino (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 | Final |
| 1 | Madison Brengle | 6 | 6 | | | | | |
| 7 | Wang Xiyu | 3 | 4 | | | | | |
| 7 | Wang Xiyu | 3 | 4 | 1 | Madison Brengle | 6 | 4 | 6 |
| | | | | 2 | Zarina Diyas | 4 | 6 | 4 |
| 4 | Beatriz Haddad Maia | 4 | 1 | 2 | Zarina Diyas | 4 | 6 | 4 |
| 2 | Zarina Diyas | 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 |
| 1 | M Brengle | 6 | 6$^1$ | 6 | | | | | | | | | | | | | | |
| | T Andrianjafitrimo | 4 | 7$^7$ | 4 | 1 | M Brengle | 7 | 1 | 6 | | | | | | | | | |
| | G Min | 6 | 3 | 3 | | Jia Lu | 5 | 6 | 2 | | | | | | | | | |
| | Jia Lu | 1 | 6 | 6 | | | | | | 1 | M Brengle | 7$^7$ | 6 | | | | | |
| WC | E Navarro | 6 | 6 | | | | | | | Q | L Chirico | 6$^5$ | 4 | | | | | |
| WC | H Baptiste | 2 | 4 | | WC | E Navarro | 4 | 6 | 4 | | | | | | | | | |
| Q | L Chirico | 6 | 6 | | Q | L Chirico | 6 | 2 | 6 | | | | | | | | | |
| 6 | M Inglis | 3 | 2 | | | | | | | | | | | | 1 | M Brengle | 6 | 6 |
| 3 | K Kučová | 4 | 0$^r$ | | | | | | | | | | | | 7 | Xiy Wang | 3 | 4 |
| WC | C Harrison | 6 | 0 | | WC | C Harrison | 7 | 6 | | | | | | | | | | |
| | K Nara | 6$^2$ | 4 | | | C Dolehide | 5 | 1 | | | | | | | | | | |
| | C Dolehide | 7$^7$ | 6 | | | | | | | WC | C Harrison | 4 | 6 | 6$^5$ | | | | |
| | L Cabrera | 7 | 6 | | | | | | | 7 | Xiy Wang | 6 | 3 | 7$^7$ | | | | |
| WC | UM Arconada | 5 | 2 | | | L Cabrera | 0 | 2 | | | | | | | | | | |
| Q | A Kiick | 0 | 0 | | 7 | Xiy Wang | 6 | 6 | | | | | | | | | | |
| 7 | Xiy Wang | 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 |
| 5 | R Zarazúa | 6 | 6 | | | | | | | | | | | | | |
| | T Maria | 2 | 0 | | 5 | R Zarazúa | 6 | 6 | | | | | | | | |
| Q | A Smith | 6 | 5 | 6 | Q | A Smith | 4 | 3 | | | | | | | | |
| Q | W Osuigwe | 0 | 7 | 4 | | | | | 5 | R Zarazúa | 0$^r$ | | | | | |
| | K Kawa | 5 | 4 | | | | | | 4 | B Haddad Maia | 3 | | | | | |
| Q | R Anderson | 7 | 6 | | Q | R Anderson | 4 | 3 | | | | | | | | |
| | L Küng | 0 | 4 | | 4 | B Haddad Maia | 6 | 6 | | | | | | | | |
| 4 | B Haddad Maia | 6 | 6 | | | | | | | | | | 4 | B Haddad Maia | 4 | 1 |
| 8 | R Marino | 3 | 6 | 2 | | | | | | | | | 2 | Z Diyas | 6 | 6 |
| | K Volynets | 6 | 2 | 6 | | K Volynets | 5 | 4 | | | | | | | | |
| Q | V Duval | 4 | 6 | 6 | Q | V Duval | 7 | 6 | | | | | | | | |
| Q | D Lao | 6 | 0 | 0 | | | | | Q | V Duval | 1 | 4 | | | | |
| | A Muhammad | 2 | 2 | | | | | | 2 | Z Diyas | 6 | 6 | | | | |
| Q | H Chang | 6 | 6 | | Q | H Chang | 4 | 5 | | | | | | | | |
| PR | P Hon | 3 | 6 | 2 | 2 | Z Diyas | 6 | 7 | | | | | | | | |
| 2 | Z Diyas | 6 | 1 | 6 | | | | | | | | | | | | |