# 2021 Platzmann-Sauerland Open – Singles

This was the first edition of the tournament.
Daniel Altmaier won the title after defeating Nicolás Jarry 7–6$^{(7–1)}$, 4–6, 6–3 in the final.

## Seeds

* Pablo Andújar (first round)
* Pedro Martínez (first round)
* Roberto Carballés Baena (second round, retired)
* Daniel Altmaier (champion)
* Hugo Dellien (withdrew)
* Juan Manuel Cerúndolo (semifinals)
* Roman Safiullin (second round)
* Robin Haase (second round, withdrew)
* Constant Lestienne (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 | Final | Final | Final | Final | Final |
| | Julian Lenz | 1 | 4 | | | | | |
| | Nicolás Jarry | 6 | 6 | | | | | |
| | Nicolás Jarry | 6 | 6 | | Nicolás Jarry | 6$^1$ | 6 | 3 |
| | | | | 4 | Daniel Altmaier | 7$^7$ | 4 | 6 |
| 4 | Daniel Altmaier | 6 | 7$^7$ | 4 | Daniel Altmaier | 7$^7$ | 4 | 6 |
| 6 | Juan Manuel Cerúndolo | 2 | 6$^4$ | | | | | |

### 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 | Semifinals | Semifinals | Semifinals |
| 1 | P Andújar | 7 | 5 | 0 | | | | | | | | | | | |
| | M Bašić | 5 | 7 | 6 | | M Bašić | 7$^7$ | 6 | | | | | | | |
| | T Lamasine | 6 | 6 | | | T Lamasine | 6$^2$ | 2 | | | | | | | |
| | E Karlovskiy | 3 | 3 | | | | | | | M Bašić | 5 | 5 | | | |
| | J Lenz | 5 | 7 | 6 | | | | | | J Lenz | 7 | 7 | | | |
| WC | S Mochizuki | 7 | 5 | 2 | | J Lenz | 5 | 6 | 6 | | | | | | |
| | A Menéndez Maceiras | 2 | 7$^7$ | 4 | 7 | R Safiullin | 7 | 4 | 2 | | | | | | |
| 7 | R Safiullin | 6 | 6$^0$ | 6 | | | | | | | | | J Lenz | 1 | 4 |
| 3 | R Carballés Baena | 6 | 7$^7$ | | | | | | | | | | N Jarry | 6 | 6 |
| Alt | N Kicker | 4 | 6$^3$ | | 3 | R Carballés Baena | 1$^r$ | | | | | | | | |
| | N Jarry | 1 | 7$^7$ | 7$^8$ | | N Jarry | 5 | | | | | | | | |
| | L Klein | 6 | 6$^5$ | 6$^6$ | | | | | | N Jarry | 6 | 7$^7$ | | | |
| | D Ajduković | 6 | 7 | | | | | | | D Ajduković | 4 | 6$^5$ | | | |
| | E Furness | 3 | 5 | | | D Ajduković | 6 | 6 | | | | | | | |
| Alt | J Sels | 3 | 5 | | 9 | C Lestienne | 2 | 4 | | | | | | | |
| 9 | C Lestienne | 6 | 7 | | | | | | | | | | | | |

### Bottom 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 |
| 8 | R Haase | 6 | 6 | | | | | | | | | | | | | | |
| | R Cid Subervi | 3 | 1 | | 8 | R Haase | | | | | | | | | | | |
| Q | J Barranco Cosano | 6 | 6 | | Q | J Barranco Cosano | w/o | | | | | | | | | | |
| | F Mena | 3 | 4 | | | | | | Q | J Barranco Cosano | 4 | 7$^7$ | 5 | | | | |
| | M Zverev | 3 | 1 | | | | | | 4 | D Altmaier | 6 | 6$^5$ | 7 | | | | |
| PR | J Cagnina | 6 | 6 | | PR | J Cagnina | 6$^1$ | 3 | | | | | | | | | |
| Q | GA Olivieri | 2 | 2 | | 4 | D Altmaier | 7$^7$ | 6 | | | | | | | | | |
| 4 | D Altmaier | 6 | 6 | | | | | | | | | | | 4 | D Altmaier | 6 | 7$^7$ |
| 6 | JM Cerúndolo | 6 | 6 | | | | | | | | | | | 6 | JM Cerúndolo | 2 | 6$^4$ |
| | M Vrbenský | 4 | 2 | | 6 | JM Cerúndolo | 6 | 6 | | | | | | | | | |
| Q | FC Jianu | 7 | 3 | 6 | Q | FC Jianu | 2 | 2 | | | | | | | | | |
| WC | R Molleker | 5 | 6 | 3 | | | | | 6 | JM Cerúndolo | 3 | 6 | 6 | | | | |
| Q | M Martineau | 6 | 6 | | | | | | | C Ugo Carabelli | 6 | 3 | 2 | | | | |
| WC | M Möller | 0 | 2 | | Q | M Martineau | 4 | 6$^5$ | | | | | | | | | |
| | C Ugo Carabelli | 6 | 4 | 7$^7$ | | C Ugo Carabelli | 6 | 7$^7$ | | | | | | | | | |
| 2 | P Martínez | 2 | 6 | 6$^5$ | | | | | | | | | | | | | |