INDIAN WELLS (AFP) — Defending champion Carlos Alcaraz fought off swarming bees and Alexander Zverev on Thursday to set up a semifinal clash with Jannik Sinner at Indian Wells.

World No. 2 Alcaraz was stung on the forehead and temporarily forced from the court as a "bee invasion" halted his quarterfinal against Germany's Zverev with just two games completed.

He looked none the worse for wear when play resumed after a delay of almost two hours, polishing off a 6-3, 6-1 victory and avenging a quarter-final loss to Zverev at the Australian Open.

Sinner powered into the semi-finals with a 6-3, 6-3 victory over Czech Jiri Lehecka pushing his match win streak to 19.

Sinner's run stretches back through last year's Davis Cup finals and includes a perfect 16-0 record in 2024.

In the semifinals, he will be out to turn the tables on Alcaraz, who beat him at the same stage last year on the way to the title in the California desert.

Alcaraz said he never imagined his title defense would find him ducking for cover amid a swarm of bees.

He and Zverev were just two games into their match when the bees overwhelmed the proceedings, Alcaraz swatting and swiping at the insects after being stung on the forehead.

The bees swarmed the remote-controlled "spider cam" and Alcaraz and Zverev had already run for cover when chair umpire Mohamed Lahyani announced "Ladies and gentlemen, play is suspended due to bee invasion."

"For sure the most unusual match I have ever played in my career," he said, recalling that he noticed the bees after winning a point on serve in the third game.

"I thought it was just a few of them, not too many," he added.

"But I saw the sky and there were thousands, thousands flying, stuck in my hair, going to me. It was crazy."

"I tried to stay away from them, but it was impossible."