# 2021 Murcia Open – Singles

Roberto Carballés Baena was the defending champion but lost in the final to Tallon Griekspoor.
Griekspoor won the title after defeating Carballés Baena 3–6, 7–5, 6–3 in the final.

## Seeds

* Roberto Carballés Baena (final)
* Tallon Griekspoor (champion)
* Marc Polmans (first round)
* Mario Vilella Martínez (first round)
* Marco Trungelliti (second round, withdrew)
* Ramkumar Ramanathan (first round)
* Filip Horanský (second round)
* Mathias Bourgue (semifinals, retired)

## 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 | Roberto Carballés Baena | 6 | 3 | | | | | |
| 8 | Mathias Bourgue | 3 | 0$^r$ | | | | | |
| 8 | Mathias Bourgue | 3 | 0$^r$ | 1 | Roberto Carballés Baena | 6 | 5 | 3 |
| | | | | 2 | Tallon Griekspoor | 3 | 7 | 6 |
| | Flavio Cobolli | 6$^4$ | 1 | 2 | Tallon Griekspoor | 3 | 7 | 6 |
| 2 | Tallon Griekspoor | 7$^7$ | 6 | | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | R Carballés Baena | 6 | 6 | | | | | | | | | | | | | | |
| WC | P Llamas Ruiz | 3 | 2 | | 1 | R Carballés Baena | 6 | 6 | | | | | | | | | |
| WC | D Rincón | 3 | 2 | | Q | A Rybakov | 2 | 2 | | | | | | | | | |
| Q | A Rybakov | 6 | 6 | | | | | | 1 | R Carballés Baena | 6 | 6 | | | | | |
| | E Furness | 7 | 4 | 6 | | | | | | E Furness | 1 | 0 | | | | | |
| | J Barranco Cosano | 5 | 6 | 4 | | E Furness | w/o | | | | | | | | | | |
| | A Shevchenko | 6$^3$ | 6$^1$ | | 5 | M Trungelliti | | | | | | | | | | | |
| 5 | M Trungelliti | 7$^7$ | 7$^7$ | | | | | | | | | | | 1 | R Carballés Baena | 6 | 3 |
| 3 | M Polmans | 6 | 4 | 4 | | | | | | | | | | 8 | M Bourgue | 3 | 0$^r$ |
| Q | Em Nava | 3 | 6 | 6 | Q | Em Nava | 5 | 3 | | | | | | | | | |
| PR | J De Loore | 6 | 2 | 3 | | A Collarini | 7 | 6 | | | | | | | | | |
| | A Collarini | 4 | 6 | 6 | | | | | | A Collarini | 6 | 4 | 4 | | | | |
| PR | Jeroen Vanneste | 4 | 6 | 3 | | | | | 8 | M Bourgue | 2 | 6 | 6 | | | | |
| | R Ortega Olmedo | 6 | 3 | 6 | | R Ortega Olmedo | 6$^4$ | 4 | | | | | | | | | |
| | J de Jong | 6$^0$ | 5 | | 8 | M Bourgue | 7$^7$ | 6 | | | | | | | | | |
| 8 | M Bourgue | 7$^7$ | 7 | | | | | | | | | | | | | | |

### 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 |
| 7 | F Horanský | 3 | 6 | 6 | | | | | | | | | | | | | | |
| Q | F Passaro | 6 | 3 | 2 | 7 | F Horanský | 4 | 6 | 4 | | | | | | | | | |
| | N Kuhn | 6 | 6 | | | N Kuhn | 6 | 3 | 6 | | | | | | | | | |
| | T Skatov | 2 | 4 | | | | | | | | N Kuhn | 5 | 1 | | | | | |
| | D Svrčina | 2 | 5 | | | | | | | | F Cobolli | 7 | 6 | | | | | |
| | R Brancaccio | 6 | 7 | | | R Brancaccio | 6$^7$ | 6 | 6$^5$ | | | | | | | | | |
| | F Cobolli | 7 | 6 | | | F Cobolli | 7$^9$ | 2 | 7$^7$ | | | | | | | | | |
| 4 | M Vilella Martínez | 5 | 3 | | | | | | | | | | | | | F Cobolli | 6$^4$ | 1 |
| 6 | R Ramanathan | 6 | 4 | 3 | | | | | | | | | | | 2 | T Griekspoor | 7$^7$ | 6 |
| | M Zekić | 3 | 6 | 6 | | M Zekić | 6 | 6 | | | | | | | | | | |
| Q | M Rosenkranz | 6 | 6 | | Q | M Rosenkranz | 4 | 4 | | | | | | | | | | |
| | M Martineau | 0 | 4 | | | | | | | | M Zekić | 0 | 6 | 3 | | | | |
| | A Ritschard | 6 | 7$^8$ | | | | | | | 2 | T Griekspoor | 6 | 0 | 6 | | | | |
| WC | Á López San Martín | 1 | 6$^6$ | | | A Ritschard | 6$^3$ | 3 | | | | | | | | | | |
| | N Sánchez Izquierdo | 3 | 1 | | 2 | T Griekspoor | 7$^7$ | 6 | | | | | | | | | | |
| 2 | T Griekspoor | 6 | 6 | | | | | | | | | | | | | | | |