# 2023 Sparkassen ATP Challenger – Singles

Borna Gojo was the defending champion but chose not to defend his title.
Lukáš Klein won the title after defeating Maks Kaśnikowski 6–7$^{(4–7)}$, 7–6$^{(7–4)}$, 7–6$^{(8–6)}$ in the final.

## Seeds

* Abdullah Shelbayh (second round)
* Gauthier Onclin (first round)
* Federico Gaio (semifinals)
* Francesco Maestrelli (first round)
* Mark Lajal (second round)
* Alejandro Moro Cañas (first round)
* Stefano Napolitano (first round)
* Illya Marchenko (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 | Final |
| Q | Lukáš Klein | 6 | 7$^7$ | | | | | | |
| | Billy Harris | 3 | 6$^5$ | | | | | | |
| | Billy Harris | 3 | 6$^5$ | | Q | Lukáš Klein | 6$^4$ | 7$^7$ | 7$^8$ |
| | | | | | | Maks Kaśnikowski | 7$^7$ | 6$^4$ | 6$^6$ |
| 3 | Federico Gaio | 3 | 7 | 2 | | Maks Kaśnikowski | 7$^7$ | 6$^4$ | 6$^6$ |
| | Maks Kaśnikowski | 6 | 5 | 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 | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | A Shelbayh | 6 | 6 | | | | | | | | | | | | | | | |
| | M Efstathiou | 1 | 2 | | 1 | A Shelbayh | 6 | 3 | 4 | | | | | | | | | |
| | Y Demin | 6$^3$ | 4 | | Alt | E Dalla Valle | 4 | 6 | 6 | | | | | | | | | |
| Alt | E Dalla Valle | 7$^7$ | 6 | | | | | | | Alt | E Dalla Valle | 3 | 2 | | | | | |
| Alt | A Paulson | 5 | 4 | | | | | | | Q | L Klein | 6 | 6 | | | | | |
| Q | L Klein | 7 | 6 | | Q | L Klein | 7$^7$ | 7$^7$ | | | | | | | | | | |
| Q | M Bašić | 7$^7$ | 6 | | Q | M Bašić | 6$^5$ | 6$^3$ | | | | | | | | | | |
| 6 | A Moro Cañas | 6$^3$ | 3 | | | | | | | | | | | | Q | L Klein | 6 | 7$^7$ |
| 4 | F Maestrelli | 6 | 6$^4$ | 1 | | | | | | | | | | | | B Harris | 3 | 6$^5$ |
| | A Bellier | 4 | 7$^7$ | 6 | | A Bellier | 4 | 4 | | | | | | | | | | |
| Q | Ryan Nijboer | 3 | 6$^7$ | | Q | D Glinka | 6 | 6 | | | | | | | | | | |
| Q | D Glinka | 6 | 7$^9$ | | | | | | | Q | D Glinka | 6$^3$ | 6 | 3 | | | | |
| Q | Hynek Bartoň | 6$^5$ | 7$^7$ | 6 | | | | | | | B Harris | 7$^7$ | 4 | 6 | | | | |
| | D Jordà Sanchis | 7$^7$ | 6$^4$ | 3 | Q | H Bartoň | 2 | 6$^3$ | | | | | | | | | | |
| | B Harris | 7 | 6 | | | B Harris | 6 | 7$^7$ | | | | | | | | | | |
| 7 | S Napolitano | 5 | 3 | | | | | | | | | | | | | | | |

### 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 | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 8 | I Marchenko | 6 | 6 | | | | | | | | | | | | | | | |
| WC | L Rottoli | 4 | 4 | | 8 | I Marchenko | 6 | 2 | 6$^5$ | | | | | | | | | |
| Q | Luca Giacomini | 6 | 6 | | Q | L Giacomini | 4 | 6 | 7$^7$ | | | | | | | | | |
| | L Wessels | 3 | 4 | | | | | | | Q | L Giacomini | 6$^3$ | 6$^2$ | | | | | |
| WC | F Forti | 7$^7$ | 6 | | | | | | | 3 | F Gaio | 7$^7$ | 7$^7$ | | | | | |
| | N Gombos | 6$^5$ | 4 | | WC | F Forti | 6 | 3 | 3 | | | | | | | | | |
| | M Neuchrist | 4 | 4 | | 3 | F Gaio | 3 | 6 | 6 | | | | | | | | | |
| 3 | F Gaio | 6 | 6 | | | | | | | | | | | 3 | F Gaio | 3 | 7 | 2 |
| 5 | M Lajal | 6 | 6 | | | | | | | | | | | | M Kaśnikowski | 6 | 5 | 6 |
| | K Żuk | 3 | 4 | | 5 | M Lajal | 6 | 4 | 2 | | | | | | | | | |
| | M Bourgue | 6 | 6$^6$ | 6 | | M Bourgue | 3 | 6 | 6 | | | | | | | | | |
| | J Sousa | 3 | 7$^8$ | 4 | | | | | | | M Bourgue | 6$^3$ | 3 | | | | | |
| | M Geerts | 6 | 6 | | | | | | | | M Kaśnikowski | 7$^7$ | 6 | | | | | |
| WC | Lorenzo Carboni | 4 | 1 | | | M Geerts | 7 | 3 | 6$^4$ | | | | | | | | | |
| | M Kaśnikowski | 6 | 6 | | | M Kaśnikowski | 5 | 6 | 7$^7$ | | | | | | | | | |
| 2 | G Onclin | 1 | 4 | | | | | | | | | | | | | | | |