# 2020 Slovak Open – Singles

Dennis Novak was the defending champion but chose not to defend his title.
Maximilian Marterer won the title after defeating Tomáš Macháč 6–7$^{(3–7)}$, 6–2, 7–5 in the final.

## Seeds

* Emil Ruusuvuori (quarterfinals)
* Yasutaka Uchiyama (first round)
* Kamil Majchrzak (second round)
* Antoine Hoang (semifinals)
* Henri Laaksonen (first round)
* Nikola Milojević (second round)
* Federico Gaio (first round)
* Lorenzo Giustino (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 |
| WC | Lukáš Klein | 6$^5$ | 2 | | | | | |
| Q | Tomáš Macháč | 7$^7$ | 6 | | | | | |
| Q | Tomáš Macháč | 7$^7$ | 6 | Q | Tomáš Macháč | 7$^7$ | 2 | 5 |
| | | | | PR | Maximilian Marterer | 6$^3$ | 6 | 7 |
| 4 | Antoine Hoang | 3 | 4 | PR | Maximilian Marterer | 6$^3$ | 6 | 7 |
| PR | Maximilian Marterer | 6 | 6 | | | | | |

### 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 | E Ruusuvuori | 6 | 6 | | | | | | | | | | | | | | |
| | S Diez | 3 | 3 | | 1 | E Ruusuvuori | 6 | 6 | | | | | | | | | |
| | A Rinderknech | 6 | 6$^5$ | 7 | | A Rinderknech | 1 | 4 | | | | | | | | | |
| | L Broady | 4 | 7$^7$ | 5 | | | | | | 1 | E Ruusuvuori | 4 | 5 | | | | |
| | F Horanský | 4 | 4 | | | | | | | WC | L Klein | 6 | 7 | | | | |
| WC | L Klein | 6 | 6 | | WC | L Klein | 6 | 6 | | | | | | | | | |
| | Y Maden | 5 | 6 | 4 | 8 | L Giustino | 4 | 3 | | | | | | | | | |
| 8 | L Giustino | 7 | 3 | 6 | | | | | | | | | | WC | L Klein | 6$^5$ | 2 |
| 3 | K Majchrzak | 6 | 6 | | | | | | | | | | | Q | T Macháč | 7$^7$ | 6 |
| WC | A Molčan | 2 | 1 | | 3 | K Majchrzak | 5 | 7$^7$ | 1 | | | | | | | | |
| Q | B Schnur | 4 | 4 | | Q | T Macháč | 7 | 6$^5$ | 6 | | | | | | | | |
| Q | T Macháč | 6 | 6 | | | | | | | Q | T Macháč | 6 | 6 | | | | |
| WC | J Lehečka | 6 | 4 | 6$^5$ | | | | | | Alt | M Viola | 2 | 4 | | | | |
| Alt | M Viola | 2 | 6 | 7$^7$ | Alt | M Viola | 7$^7$ | 4 | 6 | | | | | | | | |
| SE | A Arnaboldi | 5 | 6$^4$ | | 6 | N Milojević | 6$^5$ | 6 | 3 | | | | | | | | |
| 6 | N Milojević | 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 | Semifinals | Semifinals | Semifinals | Semifinals |
| 5 | H Laaksonen | 3 | 6 | 3 | | | | | | | | | | | | |
| | B van de Zandschulp | 6 | 3 | 6 | | B van de Zandschulp | 6$^0$ | 7$^8$ | 1 | | | | | | | |
| Q | M Bourgue | 7$^7$ | 6 | | Q | M Bourgue | 7$^7$ | 6$^6$ | 6 | | | | | | | |
| | S Ofner | 6$^4$ | 1 | | | | | | | Q | M Bourgue | | | | | |
| | M Cressy | 6 | 4 | 6$^4$ | | | | | | 4 | A Hoang | w/o | | | | |
| | R Marcora | 2 | 6 | 7$^7$ | | R Marcora | 3 | 4 | | | | | | | | |
| SE | Q Halys | 3 | 3 | | 4 | A Hoang | 6 | 6 | | | | | | | | |
| 4 | A Hoang | 6 | 6 | | | | | | | | | | 4 | A Hoang | 3 | 4 |
| 7 | F Gaio | 3 | 4 | | | | | | | | | | PR | M Marterer | 6 | 6 |
| | R Safiullin | 6 | 6 | | | R Safiullin | 6 | 4 | 4 | | | | | | | |
| | L Lacko | 5 | 6$^6$ | | | S Stakhovsky | 4 | 6 | 6 | | | | | | | |
| | S Stakhovsky | 7 | 7$^8$ | | | | | | | | S Stakhovsky | | | | | |
| Q | J Lenz | 5 | 4 | | | | | | | PR | M Marterer | w/o | | | | |
| PR | M Marterer | 7 | 6 | | PR | M Marterer | 7$^7$ | 6 | | | | | | | | |
| | B Rola | 7$^8$ | 6 | | | B Rola | 6$^4$ | 2 | | | | | | | | |
| 2 | Y Uchiyama | 6$^6$ | 4 | | | | | | | | | | | | | |