# 2021 Erste Bank Open – Singles

Andrey Rublev was the defending champion, but chose to compete in St. Petersburg instead.
Alexander Zverev won the title, defeating Frances Tiafoe in the final, 7–5, 6–4.

## Seeds

* Stefanos Tsitsipas (second round)
* Alexander Zverev (champion)
* Matteo Berrettini (quarterfinals)
* Casper Ruud (quarterfinals)
* Hubert Hurkacz (first round)
* Félix Auger-Aliassime (quarterfinals)
* Jannik Sinner (semifinals)
* Diego Schwartzman (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 | Final |
| Q | Frances Tiafoe | 3 | 7 | 6 | | | | |
| 7 | Jannik Sinner | 6 | 5 | 2 | | | | |
| 7 | Jannik Sinner | 6 | 5 | 2 | Q | Frances Tiafoe | 5 | 4 |
| | | | | | 2 | Alexander Zverev | 7 | 6 |
| | Carlos Alcaraz | 3 | 3 | | 2 | Alexander Zverev | 7 | 6 |
| 2 | Alexander Zverev | 6 | 6 | | | | | |

### Top half

| 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 |
| 1 | S Tsitsipas | 7$^8$ | 6 | | | | | | | | | | | | | | |
| | G Dimitrov | 6$^6$ | 4 | 1 | S Tsitsipas | 6 | 3 | 4 | | | | | | | | | |
| | D Lajović | 4 | 4 | Q | F Tiafoe | 3 | 6 | 6 | | | | | | | | | |
| Q | F Tiafoe | 6 | 6 | | | | | | Q | F Tiafoe | 6 | 7$^8$ | | | | | |
| | G Monfils | 7$^7$ | 6 | | | | | | 8 | D Schwartzman | 4 | 6$^6$ | | | | | |
| WC | L Musetti | 6$^2$ | 4 | | G Monfils | 6$^5$ | 6 | 2 | | | | | | | | | |
| | F Fognini | 2 | 5 | 8 | D Schwartzman | 7$^7$ | 4 | 6 | | | | | | | | | |
| 8 | D Schwartzman | 6 | 7 | | | | | | | | | | Q | F Tiafoe | 3 | 7 | 6 |
| 4 | C Ruud | 7 | 7$^7$ | | | | | | | | | | 7 | J Sinner | 6 | 5 | 2 |
| | L Harris | 5 | 6$^2$ | 4 | C Ruud | 7 | 4 | 6 | | | | | | | | | |
| | L Sonego | 6 | 6 | | L Sonego | 5 | 6 | 4 | | | | | | | | | |
| LL | D Koepfer | 4 | 3 | | | | | | 4 | C Ruud | 5 | 1 | | | | | |
| WC | D Novak | 7$^7$ | 7$^7$ | | | | | | 7 | J Sinner | 7 | 6 | | | | | |
| Q | G Mager | 6$^4$ | 6$^4$ | WC | D Novak | 4 | 2 | | | | | | | | | | |
| | R Opelka | 4 | 2 | 7 | J Sinner | 6 | 6 | | | | | | | | | | |
| 7 | J Sinner | 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 |
| 5 | H Hurkacz | 4 | 7$^8$ | 3 | | | | | | | | | | | | | | |
| WC | A Murray | 6 | 6$^6$ | 6 | WC | A Murray | 3 | 4 | | | | | | | | | | |
| | C Alcaraz | 6 | 6 | | | C Alcaraz | 6 | 6 | | | | | | | | | | |
| | D Evans | 4 | 3 | | | | | | | | C Alcaraz | 6 | 6$^2$ | 7$^7$ | | | | |
| | N Basilashvili | 7 | 4 | 6 | | | | | | 3 | M Berrettini | 1 | 7$^7$ | 6$^5$ | | | | |
| | P Carreño Busta | 5 | 6 | 3 | | N Basilashvili | 7$^7$ | 2 | 3 | | | | | | | | | |
| Q | A Popyrin | 6$^3$ | 3 | | 3 | M Berrettini | 6$^5$ | 6 | 6 | | | | | | | | | |
| 3 | M Berrettini | 7$^7$ | 6 | | | | | | | | | | | | | C Alcaraz | 3 | 3 |
| 6 | F Auger-Aliassime | 6 | 6 | | | | | | | | | | | | 2 | A Zverev | 6 | 6 |
| SE | R Berankis | 3 | 2 | | 6 | F Auger-Aliassime | 2 | 7$^8$ | 6 | | | | | | | | | |
| | C Norrie | 7$^7$ | 6 | | | C Norrie | 6 | 6$^6$ | 4 | | | | | | | | | |
| | M Fucsovics | 6$^4$ | 1 | | | | | | | 6 | F Auger-Aliassime | 4 | 6 | 3 | | | | |
| | A de Minaur | 6 | 7$^7$ | | | | | | | 2 | A Zverev | 6 | 3 | 6 | | | | |
| Q | K Anderson | 3 | 6$^3$ | | | A de Minaur | 2 | 6 | 2 | | | | | | | | | |
| | F Krajinović | 2 | 5 | | 2 | A Zverev | 6 | 3 | 6 | | | | | | | | | |
| 2 | A Zverev | 6 | 7 | | | | | | | | | | | | | | | |

## Qualifying
### Seeds

* Frances Tiafoe (qualified)
* Marcos Giron (first round)
* Kevin Anderson (qualified)
* Dominik Koepfer (qualifying competition, lucky loser)
* Gianluca Mager (qualified)
* Alexei Popyrin (qualified)
* Roberto Carballés Baena (qualifying competition)
* Peter Gojowczyk (first round)

### Qualifiers

* Frances Tiafoe
* Alexei Popyrin
* Kevin Anderson
* Gianluca Mager

### Lucky loser

* Dominik Koepfer

### Qualifying draw
#### First qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 1 | Frances Tiafoe | 6 | 3 | 6 | | | | | |
| | Alex Molčan | 4 | 6 | 1 | | | | | |
| | Alex Molčan | 4 | 6 | 1 | 1 | Frances Tiafoe | 6$^5$ | 6 | 6 |
| | | | | | WC | Lucas Miedler | 7$^7$ | 4 | 3 |
| WC | Lucas Miedler | 7$^7$ | 6 | | WC | Lucas Miedler | 7$^7$ | 4 | 3 |
| 8 | Peter Gojowczyk | 6$^4$ | 2 | | | | | | |

#### Second qualifier

| First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 2 | Marcos Giron | 6$^5$ | 4 | | | | | |
| | Norbert Gombos | 7$^7$ | 6 | | | | | |
| | Norbert Gombos | 7$^7$ | 6 | | Norbert Gombos | 6$^3$ | 7$^7$ | 5 |
| | | | | 6 | Alexei Popyrin | 7$^7$ | 6$^0$ | 7 |
| | Feliciano López | 5 | 6$^8$ | 6 | Alexei Popyrin | 7$^7$ | 6$^0$ | 7 |
| 6 | Alexei Popyrin | 7 | 7$^{10}$ | | | | | |

#### Third qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 3 | Kevin Anderson | 6 | 6 | | | | | | |
| Alt | Jurij Rodionov | 1 | 4 | | | | | | |
| Alt | Jurij Rodionov | 1 | 4 | | 3 | Kevin Anderson | 7 | 4 | 7$^7$ |
| | | | | | 7 | Roberto Carballés Baena | 5 | 6 | 6$^5$ |
| WC | Dominic Stricker | 4 | 6 | 1 | 7 | Roberto Carballés Baena | 5 | 6 | 6$^5$ |
| 7 | Roberto Carballés Baena | 6 | 3 | 6 | | | | | |

#### Fourth qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 4 | Dominik Koepfer | 7$^8$ | 6 | | | | | | |
| Alt | Alex Bolt | 6$^6$ | 1 | | | | | | |
| Alt | Alex Bolt | 6$^6$ | 1 | | 4 | Dominik Koepfer | 3 | 6 | 3 |
| | | | | | 5 | Gianluca Mager | 6 | 3 | 6 |
| WC | Alexander Erler | 7$^7$ | 2 | 4 | 5 | Gianluca Mager | 6 | 3 | 6 |
| 5 | Gianluca Mager | 6$^2$ | 6 | 6 | | | | | |