2017 Croatia Open Umag – Singles
| Singles | |
|---|---|
| 2017 Croatia Open Umag | |
| Champion | Andrey Rublev |
| Runner-up | Paolo Lorenzi |
| Score | 6–4, 6–2 |
| Draw | 28 (4 Q / 3 WC ) |
| Seeds | 8 |
Fabio Fognini was the defending champion, but lost in the quarterfinals to lucky loser Andrey Rublev.
Rublev went on to win his first ATP World Tour title, defeating Paolo Lorenzi in the final, 6–4, 6–2. He was the seventh lucky loser in ATP history to win a tour-level title and the first to do so since Rajeev Ram at 2009 Newport.