# 2021 Almaty Challenger II – Singles

Zizou Bergs was the defending champion but lost in the second round to Pavel Kotov.
Jesper de Jong won the title after defeating Marcelo Tomás Barrios Vera 6–1, 6–2 in the final.

## Seeds

* Andrej Martin (semifinals)
* Mohamed Safwat (second round)
* Kimmer Coppejans (first round)
* Lorenzo Giustino (first round)
* Dmitry Popko (second round)
* Denis Istomin (first round)
* João Menezes (second round)
* Brayden Schnur (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 | Final | Final | Final | Final |
| 1 | Andrej Martin | 3 | 0 | | | | |
| | Marcelo Tomás Barrios Vera | 6 | 6 | | | | |
| | Marcelo Tomás Barrios Vera | 6 | 6 | | Marcelo Tomás Barrios Vera | 1 | 2 |
| | | | | Q | Jesper de Jong | 6 | 6 |
| Q | Jesper de Jong | 6 | 7$^7$ | Q | Jesper de Jong | 6 | 6 |
| | Mirza Bašić | 4 | 6$^3$ | | | | |

### 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 | A Martin | 6 | 7$^{13}$ | | | | | | | | | | | | | | | |
| Q | V Sachko | 4 | 6$^{11}$ | | 1 | A Martin | 6 | 6 | | | | | | | | | | |
| | E Tiurnev | 7$^{12}$ | 3 | 5 | WC | D Yevseyev | 4 | 2 | | | | | | | | | | |
| WC | D Yevseyev | 6$^{10}$ | 6 | 7 | | | | | | 1 | A Martin | 7$^9$ | 7 | | | | | |
| | C-h Tseng | 5 | 6 | 2 | | | | | | 8 | B Schnur | 6$^7$ | 5 | | | | | |
| | C Gimeno Valero | 7 | 4 | 6 | | C Gimeno Valero | 4 | 6$^6$ | | | | | | | | | | |
| | A Menéndez Maceiras | 5 | 3 | | 8 | B Schnur | 6 | 7$^8$ | | | | | | | | | | |
| 8 | B Schnur | 7 | 6 | | | | | | | | | | | | 1 | A Martin | 3 | 0 |
| 4 | L Giustino | 6$^3$ | 4 | | | | | | | | | | | | | MT Barrios Vera | 6 | 6 |
| | P Kotov | 7$^7$ | 6 | | | P Kotov | 6 | 4 | 6 | | | | | | | | | |
| | Z Bergs | 6 | 5 | 6 | | Z Bergs | 3 | 6 | 2 | | | | | | | | | |
| Q | E Kırkın | 4 | 7 | 2 | | | | | | | P Kotov | 3 | 6 | 4 | | | | |
| | MT Barrios Vera | 7$^7$ | 6 | | | | | | | | MT Barrios Vera | 6 | 2 | 6 | | | | |
| Q | V Orlov | 6$^3$ | 2 | | | MT Barrios Vera | 6 | 6 | | | | | | | | | | |
| | N Serdarušić | 4 | 3 | | 5 | D Popko | 4 | 1 | | | | | | | | | | |
| 5 | D Popko | 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 | Semifinals | Semifinals | Semifinals | Semifinals |
| 6 | D Istomin | 3 | 1 | | | | | | | | | | | | | | |
| | R Bonadio | 6 | 6 | | | R Bonadio | 6 | 7$^7$ | | | | | | | | | |
| | T-l Wu | 4 | 5 | | LL | FC Jianu | 1 | 6$^2$ | | | | | | | | | |
| LL | FC Jianu | 6 | 7 | | | | | | | | R Bonadio | 6$^6$ | 2 | | | | |
| | P Krstin | 0$^r$ | | | | | | | | Q | J de Jong | 7$^8$ | 6 | | | | |
| | T Gabashvili | 3 | | | | T Gabashvili | 3 | 2 | | | | | | | | | |
| Q | J de Jong | 6 | 6 | | Q | J de Jong | 6 | 6 | | | | | | | | | |
| 3 | K Coppejans | 4 | 2 | | | | | | | | | | | Q | J de Jong | 6 | 7$^7$ |
| 7 | J Menezes | 6 | 6 | | | | | | | | | | | | M Bašić | 4 | 6$^3$ |
| WC | Dostanbek Tashbulatov | 2 | 0 | | 7 | J Menezes | 6 | 2 | 5 | | | | | | | | |
| | M Bašić | 6 | 6 | | | M Bašić | 4 | 6 | 7 | | | | | | | | |
| SE | T Skatov | 3 | 1 | | | | | | | | M Bašić | 6 | 7 | | | | |
| | GM Moroni | 4 | 6 | 4 | | | | | | | GM Moroni | 3 | 5 | | | | |
| | D Kuzmanov | 6 | 3 | 1$^r$ | | GM Moroni | 4 | 6 | 6 | | | | | | | | |
| WC | B Zhukayev | 4 | 4 | | 2 | M Safwat | 6 | 3 | 3 | | | | | | | | |
| 2 | M Safwat | 6 | 6 | | | | | | | | | | | | | | |