# 2023 Croatia Open Umag – Singles

Alexei Popyrin defeated Stan Wawrinka in the final, 6–7$^{(5–7)}$, 6–3, 6–4 to win the singles tennis title at the 2023 Croatia Open Umag. It was his second ATP Tour singles title.
Jannik Sinner was the reigning champion, but chose not to defend his title.

## Seeds

The top four seeds received a bye into the second round.
* Jiří Lehečka (quarterfinals)
* Lorenzo Sonego (semifinals)
* Sebastian Ofner (second round)
* Roberto Carballés Baena (quarterfinals)
* Christopher O'Connell (first round)
* Stan Wawrinka (final)
* Matteo Arnaldi (semifinals)
* Albert Ramos Viñolas (first 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 |
| 7 | Matteo Arnaldi | 7$^7$ | 5 | 3 | | | | | |
| | Alexei Popyrin | 6$^2$ | 7 | 6 | | | | | |
| | Alexei Popyrin | 6$^2$ | 7 | 6 | | Alexei Popyrin | 6$^5$ | 6 | 6 |
| | | | | | 6 | Stan Wawrinka | 7$^7$ | 3 | 4 |
| 6 | Stan Wawrinka | 6 | 6 | | 6 | Stan Wawrinka | 7$^7$ | 3 | 4 |
| 2 | Lorenzo Sonego | 3 | 4 | | | | | | |

### Top half

| 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 | Semifinals |
| | | | | 1 | J Lehečka | 6 | 7 | | | | | | | | | | |
| | D Thiem | 6 | 7 | | D Thiem | 3 | 5 | | | | | | | | | | |
| Q | F Bagnis | 4 | 5 | | | | | 1 | J Lehečka | 6 | 2 | 4 | | | | | |
| | M Čilić | 4 | 3 | | | | | 7 | M Arnaldi | 3 | 6 | 6 | | | | | |
| Q | F Cobolli | 6 | 6 | Q | F Cobolli | 3 | 6$^5$ | | | | | | | | | | |
| Q | J de Jong | 3 | 2 | 7 | M Arnaldi | 6 | 7$^7$ | | | | | | | | | | |
| 7 | M Arnaldi | 6 | 6 | | | | | | | | | | 7 | M Arnaldi | 7$^7$ | 5 | 3 |
| | | | | | | | | | | | | | | A Popyrin | 6$^2$ | 7 | 6 |
| | | | | 3 | S Ofner | 4 | 1 | | | | | | | | | | |
| | A Popyrin | 6 | 7 | | A Popyrin | 6 | 6 | | | | | | | | | | |
| | B Bonzi | 4 | 5 | | | | | | A Popyrin | 7$^7$ | 7 | | | | | | |
| WC | D Ajduković | 1 | 2 | | | | | WC | D Prižmić | 6$^2$ | 5 | | | | | | |
| WC | D Prižmić | 6 | 6 | WC | D Prižmić | 6 | 6 | | | | | | | | | | |
| | Z Piros | 6 | 6 | | Z Piros | 2 | 3 | | | | | | | | | | |
| 5 | C O'Connell | 3 | 4 | | | | | | | | | | | | | | |

### 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 |
| 6 | S Wawrinka | 6 | 6 | | | | | | | | | | | | | | |
| Q | F Misolic | 3 | 2 | | 6 | S Wawrinka | 7 | 6 | | | | | | | | | |
| | M-A Hüsler | 4 | 2 | | | F Coria | 5 | 1 | | | | | | | | | |
| | F Coria | 6 | 6 | | | | | | 6 | S Wawrinka | 6 | 7 | | | | | |
| | T Daniel | 1 | 7 | 6 | | | | | 4 | R Carballés Baena | 4 | 5 | | | | | |
| WC | M Landaluce | 6 | 5 | 2 | | T Daniel | 3 | 1 | | | | | | | | | |
| | | | | | 4 | R Carballés Baena | 6 | 6 | | | | | | | | | |
| | | | | | | | | | | | | | | 6 | S Wawrinka | 6 | 6 |
| 8 | A Ramos Viñolas | 3 | 6 | 3 | | | | | | | | | | 2 | L Sonego | 3 | 4 |
| | J Munar | 6 | 3 | 6 | | J Munar | 6 | 6 | | | | | | | | | |
| | F Marozsán | 6 | 6 | | | F Marozsán | 4 | 3 | | | | | | | | | |
| | JM Cerúndolo | 3 | 2 | | | | | | | J Munar | 6 | 1 | 2 | | | | |
| | M Cecchinato | 4 | 7$^7$ | 6 | | | | | 2 | L Sonego | 3 | 6 | 6 | | | | |
| | A Shevchenko | 6 | 6$^0$ | 3 | | M Cecchinato | 1 | 6$^7$ | | | | | | | | | |
| | | | | | 2 | L Sonego | 6 | 7$^9$ | | | | | | | | | |

## Qualifying
### Seeds

* Alejandro Tabilo (first round)
* Tomás Barrios Vera (qualifying competition)
* Andrea Vavassori (first round)
* Timofey Skatov (qualifying competition)
* Facundo Bagnis (qualified)
* Filip Misolic (qualified)
* Raúl Brancaccio (first round)
* Luca Nardi (first round)

### Qualifiers

* Filip Misolic
* Jesper de Jong
* Flavio Cobolli
* Facundo Bagnis

### Qualifying draw
#### First qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 1 | Alejandro Tabilo | 4 | 6 | 6$^4$ | | | | |
| | Damir Džumhur | 6 | 4 | 7$^7$ | | | | |
| | Damir Džumhur | 6 | 4 | 7$^7$ | | Damir Džumhur | 4 | 3 |
| | | | | | 6 | Filip Misolic | 6 | 6 |
| Alt | Pablo Cuevas | 5 | 2 | | 6 | Filip Misolic | 6 | 6 |
| 6 | Filip Misolic | 7 | 6 | | | | | |

#### Second qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 2 | Tomás Barrios Vera | 6 | 6 | | | | | |
| WC | Nino Serdarušić | 4 | 2 | | | | | |
| WC | Nino Serdarušić | 4 | 2 | | 2 | Tomás Barrios Vera | 2 | 4 |
| | | | | | | Jesper de Jong | 6 | 6 |
| | Jesper de Jong | 4 | 6 | 6 | | Jesper de Jong | 6 | 6 |
| 7 | Raúl Brancaccio | 6 | 2 | 3 | | | | |

#### Third qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition |
| 3 | Andrea Vavassori | 2 | 6 | 6$^6$ | | | |
| | Zdeněk Kolář | 6 | 4 | 7$^8$ | | | |
| | Zdeněk Kolář | 6 | 4 | 7$^8$ | Zdeněk Kolář | 4 | 2 |
| | | | | | Flavio Cobolli | 6 | 6 |
| | Flavio Cobolli | 6 | 7 | | Flavio Cobolli | 6 | 6 |
| 8 | Luca Nardi | 1 | 5 | | | | |

#### Fourth qualifier

| First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 4 | Timofey Skatov | 6 | 6 | | | | | |
| WC | Jerko Brkić | 2 | 2 | | | | | |
| WC | Jerko Brkić | 2 | 2 | 4 | Timofey Skatov | 7 | 4 | 2 |
| | | | | 5 | Facundo Bagnis | 5 | 6 | 6 |
| | Francesco Maestrelli | 4 | 1 | 5 | Facundo Bagnis | 5 | 6 | 6 |
| 5 | Facundo Bagnis | 6 | 6 | | | | | |