# 2021 Argentina Open – Singles

Diego Schwartzman defeated Francisco Cerúndolo in the final, 6–1, 6–2 to win the men's singles tennis title at the 2021 Argentina Open.
Casper Ruud was the defending champion, but chose not to participate.

## Seeds

The top four seeds receive a bye into the second round.
* Diego Schwartzman (champion)
* Cristian Garín (second round)
* Benoît Paire (second round)
* Miomir Kecmanović (semifinals)
* Albert Ramos Viñolas (semifinals)
* Pablo Andújar (quarterfinals)
* Laslo Đere (quarterfinals)
* Frances Tiafoe (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 |
| 1 | Diego Schwartzman | 6 | 6 | | | | | |
| 4 | Miomir Kecmanović | 0 | 4 | | | | | |
| 4 | Miomir Kecmanović | 0 | 4 | | 1 | Diego Schwartzman | 6 | 6 |
| | | | | | Q | Francisco Cerúndolo | 1 | 2 |
| Q | Francisco Cerúndolo | 7$^7$ | 3 | 6 | Q | Francisco Cerúndolo | 1 | 2 |
| 5 | Albert Ramos Viñolas | 6$^5$ | 6 | 2 | | | | |

### 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 | Semifinals | Semifinals | Semifinals | Semifinals |
| | | | | | 1 | D Schwartzman | 6 | 6 | | | | | | | | | |
| | A Martin | 4 | 3 | | Q | L Klein | 4 | 2 | | | | | | | | | |
| Q | L Klein | 6 | 6 | | | | | | | 1 | D Schwartzman | 6 | 7 | | | | |
| WC | F Díaz Acosta | 6$^5$ | 3 | | | | | | | Q | J Munar | 2 | 5 | | | | |
| Q | J Munar | 7$^7$ | 6 | | Q | J Munar | 7$^7$ | 6 | | | | | | | | | |
| SE | F Bagnis | 1 | 3 | | 8 | F Tiafoe | 6$^4$ | 4 | | | | | | | | | |
| 8 | F Tiafoe | 6 | 6 | | | | | | | | | | | 1 | D Schwartzman | 6 | 6 |
| | | | | | | | | | | | | | | 4 | M Kecmanović | 0 | 4 |
| | | | | | 4 | M Kecmanović | 5 | 6 | 6 | | | | | | | | |
| | R Carballés Baena | 2 | 3 | | | T Monteiro | 7 | 3 | 4 | | | | | | | | |
| | T Monteiro | 6 | 6 | | | | | | | 4 | M Kecmanović | 6 | 7$^8$ | | | | |
| | F Delbonis | 6 | 7$^7$ | | | | | | | 7 | L Đere | 4 | 6$^6$ | | | | |
| SE | JM Cerúndolo | 4 | 6$^2$ | | | F Delbonis | 6$^1$ | 3 | | | | | | | | | |
| | M Cecchinato | 7$^7$ | 2 | 3 | 7 | L Đere | 7$^7$ | 6 | | | | | | | | | |
| 7 | L Đere | 6$^4$ | 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 | P Andújar | 6 | 6 | | | | | | | | | | | | | | | | |
| | JI Londero | 3 | 0 | | 6 | P Andújar | 6 | 7$^7$ | | | | | | | | | | | |
| | G Mager | 7$^7$ | 6 | | | G Mager | 4 | 6$^5$ | | | | | | | | | | | |
| | S Caruso | 6$^5$ | 4 | | | | | | | 6 | P Andújar | 6 | 3 | 2 | | | | | |
| Q | F Cerúndolo | 6 | 7 | | | | | | | Q | F Cerúndolo | 1 | 6 | 6 | | | | | |
| | F Coria | 4 | 5 | | Q | F Cerúndolo | 4 | 6 | 6 | | | | | | | | | | |
| | | | | | 3 | B Paire | 6 | 3 | 1 | | | | | | | | | | |
| | | | | | | | | | | | | | | | Q | F Cerúndolo | 7$^7$ | 3 | 6 |
| 5 | A Ramos Viñolas | 2 | 6 | 6 | | | | | | | | | | | 5 | A Ramos Viñolas | 6$^5$ | 6 | 2 |
| WC | H Rune | 6 | 4 | 3 | 5 | A Ramos Viñolas | 7 | 6 | | | | | | | | | | | |
| | D Koepfer | 2 | 6 | 6 | | D Koepfer | 5 | 4 | | | | | | | | | | | |
| WC | TA Tirante | 6 | 3 | 4 | | | | | | 5 | A Ramos Viñolas | 4 | 6 | 7 | | | | | |
| | J Sousa | 2 | 0 | | | | | | | Q | S Nagal | 6 | 2 | 5 | | | | | |
| Q | S Nagal | 6 | 6 | | Q | S Nagal | 6 | 6 | | | | | | | | | | | |
| | | | | | 2 | C Garín | 4 | 3 | | | | | | | | | | | |

## Qualifying
### Seeds

* Jaume Munar (qualified)
* Hugo Dellien (first round, withdrew)
* Daniel Elahi Galán (withdrew)
* Thiago Seyboth Wild (second round)
* Jozef Kovalík (second round)
* Francisco Cerúndolo (qualified)
* Daniel Altmaier (qualifying competition)
* Leonardo Mayer (first round)

### Qualifiers

* Jaume Munar
* Francisco Cerúndolo
* Sumit Nagal
* Lukáš Klein

### Qualifying draw
#### First qualifier

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 1 | Jaume Munar | 6 | 6$^5$ | 6 | | | | | | | | | |
| WC | Nicolás Álvarez | 4 | 7$^7$ | 2 | | | | | | | | | |
| WC | Nicolás Álvarez | 4 | 7$^7$ | 2 | 1 | Jaume Munar | 5 | 6 | 2 | | | | |
| | | | | | | Sebastián Báez | 7 | 3 | 1$^r$ | | | | |
| | Sebastián Báez | 6 | 6 | | | Sebastián Báez | 7 | 3 | 1$^r$ | | | | |
| | Alejandro Tabilo | 1 | 0 | | | | | | | | | | |
| | Alejandro Tabilo | 1 | 0 | | | | | | | 1 | Jaume Munar | 6 | 6 |
| | | | | | | | | | | 7 | Daniel Altmaier | 3 | 4 |
| | Facundo Mena | 3 | 4 | | | | | | | | | | | 7 | Daniel Altmaier | 3 | 4 |
| | Juan Pablo Varillas | 6 | 6 | | | | | | | | | | |
| | Juan Pablo Varillas | 6 | 6 | | | Juan Pablo Varillas | 4 | 7$^7$ | 5 | | | | |
| | | | | | 7 | Daniel Altmaier | 6 | 6$^3$ | 7 | | | | |
| | Orlando Luz | 4 | 7 | 2 | 7 | Daniel Altmaier | 6 | 6$^3$ | 7 | | | | |
| 7 | Daniel Altmaier | 6 | 5 | 6 | | | | | | | | | |

#### Second qualifier

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 2 | Hugo Dellien | | | | | | | | | | | | |
| | Pedro Sakamoto | w/o | | | | | | | | | | | |
| | Pedro Sakamoto | w/o | | | | Pedro Sakamoto | 3 | 4 | | | | | |
| | | | | | WC | Agustín Velotti | 6 | 6 | | | | | |
| WC | Agustín Velotti | 7 | 6 | | WC | Agustín Velotti | 6 | 6 | | | | | |
| | Guido Andreozzi | 5 | 0 | | | | | | | | | | |
| | Guido Andreozzi | 5 | 0 | | | | | | | WC | Agustín Velotti | 4 | 5 |
| | | | | | | | | | | 6 | Francisco Cerúndolo | 6 | 7 |
| WC | Hernán Casanova | 6 | 3 | 3 | | | | | | | | | | 6 | Francisco Cerúndolo | 6 | 7 |
| | Guilherme Clezar | 1 | 6 | 6 | | | | | | | | | |
| | Guilherme Clezar | 1 | 6 | 6 | | Guilherme Clezar | 6 | 3 | 2 | | | | |
| | | | | | 6 | Francisco Cerúndolo | 2 | 6 | 6 | | | | |
| | João Menezes | 6 | 4 | 4 | 6 | Francisco Cerúndolo | 2 | 6 | 6 | | | | |
| 6 | Francisco Cerúndolo | 4 | 6 | 6 | | | | | | | | | |

#### Third qualifier

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| Alt | Carlos Gómez-Herrera | 6$^2$ | 6 | 6$^2$ | | | | | | | | | | |
| | Sumit Nagal | 7$^7$ | 2 | 7$^7$ | | | | | | | | | | |
| | Sumit Nagal | 7$^7$ | 2 | 7$^7$ | | Sumit Nagal | 6 | 6 | | | | | | |
| | | | | | | Mario Vilella Martínez | 4 | 2 | | | | | | |
| | Mario Vilella Martínez | 6 | 7 | | | Mario Vilella Martínez | 4 | 2 | | | | | | |
| | Marcelo Tomás Barrios Vera | 4 | 5 | | | | | | | | | | | |
| | Marcelo Tomás Barrios Vera | 4 | 5 | | | | | | | | Sumit Nagal | 2 | 6 | 6 |
| | | | | | | | | | | WC | Nicolás Kicker | 6 | 2 | 3 |
| WC | Nicolás Kicker | 7 | 7 | | | | | | | | | | | | WC | Nicolás Kicker | 6 | 2 | 3 |
| | Renzo Olivo | 5 | 5 | | | | | | | | | | | |
| | Renzo Olivo | 5 | 5 | | WC | Nicolás Kicker | 1 | 7$^8$ | 7 | | | | | |
| | | | | | 5 | Jozef Kovalík | 6 | 6$^6$ | 5 | | | | | |
| | Emilio Gómez | 5 | 4 | | 5 | Jozef Kovalík | 6 | 6$^6$ | 5 | | | | | |
| 5 | Jozef Kovalík | 7 | 6 | | | | | | | | | | | |

#### Fourth qualifier

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Qualifying competition | Qualifying competition | Qualifying competition |
| 4 | Thiago Seyboth Wild | 6 | 7$^7$ | | | | | | | | | |
| Alt | Christian Lindell | 1 | 6$^4$ | | | | | | | | | |
| Alt | Christian Lindell | 1 | 6$^4$ | | 4 | Thiago Seyboth Wild | 3 | 5 | | | | |
| | | | | | | Lukáš Klein | 6 | 7 | | | | |
| | Andrea Collarini | 4 | 5 | | | Lukáš Klein | 6 | 7 | | | | |
| | Lukáš Klein | 6 | 7 | | | | | | | | | |
| | Lukáš Klein | 6 | 7 | | | | | | | Lukáš Klein | 6 | 6 |
| | | | | | | | | | | Ernesto Escobedo | 2 | 3 |
| | João Domingues | 3 | 6 | 6 | | | | | | | | | Ernesto Escobedo | 2 | 3 |
| | Tomás Martín Etcheverry | 6 | 0 | 3 | | | | | | | | |
| | Tomás Martín Etcheverry | 6 | 0 | 3 | | João Domingues | 1 | 6 | 3 | | | |
| | | | | | | Ernesto Escobedo | 6 | 1 | 6 | | | |
| | Ernesto Escobedo | 7 | 7$^7$ | | | Ernesto Escobedo | 6 | 1 | 6 | | | |
| 8 | Leonardo Mayer | 5 | 6$^5$ | | | | | | | | | |