UMAG, Croatia (AP) — Second-seeded Jannik Sinner advanced to the quarterfinals at the clay-court Croatia Open by defeating Jaume Munar 6-4, 6-4 on Wednesday.

The 20-year-old Italian, in his first match since losing in the Wimbledon quarterfinals to eventual champion Novak Djokovic, broke his Spanish opponent four times and saved two break points before converting his sixth match point.

Sinner will meet another Spaniard, Roberto Carballes Baena, who came back from a set down to upset fifth-seeded Alex Molcan 3-6, 6-2, 6-3.

Third-seeded Holger Rune extended his losing streak to seven matches after he was beaten by Bernabe Zapata Miralles of Spain 3-6, 6-3, 6-2. The 19-year-old Dane has failed to win a match since reaching the quarterfinals of the French Open.

Miralles will next play Italian qualifier Giulio Zeppieri, who beat Daniel Elahi Galan of Colombia 6-4, 3-6, 6-1.