Stefanos Tsitsipas withdraws from the ATP Finals after a back injury ends his match against Rune

Stefanos Tsitsipas withdrew from the ATP Finals with a back injury on Tuesday after playing only three games of his second match in Turin, handing Holger Rune the victory.

Tsitsipas, the 2019 champion, was trailing 2-1 in the opening set when he had a lengthy conversation with his trainer before slowly getting to his feet, shaking his head and walking over to shake Rune's hand.

That was after only 17 minutes of play and led to boos from the crowd in Turin, which instead had to settle for an exhibition match between alternates Taylor Fritz and Hubert Hurkacz.

"My apologies to all the fans and the crowd that came to support me today and watch the match. I'm really gutted that I wasn't able to finish the match," Tsitsipas said. "My doctors and the countless visits that I had in the last few days suggested that I play, they gave me the green light to go and try.