Novak Djokovic advanced to the semifinals at the Geneva Open on his 38th birthday, beating the same opponent who had eliminated him at last month's Madrid Open.

Serbia's Djokovic rallied strongly in the second set to highlight a 6-4, 6-4 win over 39th-ranked Matteo Arnaldi of Italy in Thursday's quarterfinal match in Switzerland.

The second-seeded Djokovic had smashed his racket into the ground behind the baseline, after having his serve broken to fall behind 3-1 in the second set, when he sent a backhand long.

"I'm sorry for the racket. It's not a good example particularly for the young ones," the Serbian told the crowd in French in an on-court interview. "Thank for your support. I know that, with the cold temperatures, it's not easy to stay here."

Trailing 4-1, and after seemingly straining his right knee stretching for a shot, Djokovic reeled off five straight games to wrap up the victory.

He converted his first chance on match point when Arnaldi hit a wild forehand from behind the baseline.

"It was much closer than maybe the scoring indicates," Djokovic said.

On a chilly and rainy day that was tough for higher-ranked players, top-seeded Taylor Fritz of the USA lost to sixth-seeded Hubert Hurkacz of Poland 6-3, 7-6(5), and fourth-seeded Russian Karen Khachanov fell 4-6, 6-4, 6-4 against 128th-ranked Austrian qualifier Sebastian Ofner.

Djokovic's semifinal opponent on Friday will be Cameron Norrie of Britain, who eliminated fifth-seeded Australian Alexei Popyrin 7-6(8-4), 6-4 in the evening's late match.