Dino Prizmic did not wait long to give the locals something to cheer at the 2026 Plava Laguna Croatia Open Umag.

The 20-year-old delivered a high-class first-round performance on Monday night at his home ATP 250 event, where he overwhelmed eighth seed Vit Kopriva 6-1, 6-3. Prizmic struck the ball fiercely from the baseline from the opening game of his first Lexus ATP Head2Head meeting with Czechia’s Kopriva: The Croatian powered to the first five games of the match to seize control and barely looked back to set a second-round clash with Alex Molcan or Valentin Royer.

“Today I had a very tough opponent, so I just tried to play my game and tried to stay focused every point,” Prizmic, who converted all four break points he earned against Kopriva according to Infosys ATP Stats, said in his on-court interview. “I’m happy about this performance today for the first match.”

The No. 84 player in the PIF ATP Rankings, Prizmic has now notched a personal-best 13 tour-level wins in 2026, highlighted by his upset of Novak Djokovic en route to the fourth round at the Internazionali BNL d'Italia in Rome. A competitor at the 2025 Next Gen ATP Finals, the Croatian will be aiming to reach the Umag quarter-finals for the third consecutive year when he steps on court to face Molcan or Royer.

Earlier in Umag, Luca Van Assche pulled off one of the more remarkable ATP Tour comebacks of the season so far to book his second-round berth. The 22-year-old Frenchman, who retired from his first-round match at Wimbledon two weeks ago due to a back injury, rallied from a set and a double break down to defeat Dusan Lajovic 2-6, 7-5, 6-4.

Van Assche’s reward for his first-round resilience is a meeting with his countryman Titouan Droguet or fifth seed Alexander Blockx. Damir Dzumhur and Marco Trungelliti were the other Day 1 winners on Croatia’s Adriatic coast: Dzumhur defeated Henrique Rocha 6-2, 6-1 to advance to face sixth seed Fabian Marozsan or Juan Carlos Prado Angelo, while Trungelliti downed Kyrian Jacquet 6-2, 6-3 to set a showdown with second seed Alejandro Davidovich Fokina.