World No.1 Jannik Sinner reached the Wimbledon quarter-finals in dramatic but bittersweet circumstances on Monday after Grigor Dimitrov retired injured while leading their fourth-round clash.

Dimitrov, the 19th seed, had stunned Centre Court by taking the first two sets 6-3, 7-5 and going up 2-2 in the third before collapsing in pain, clutching his chest and repeating, “my pec, my pec.”

A visibly concerned Sinner crossed the net to check on his opponent as Dimitrov wept courtside.

“I don’t take this as a win at all,” Sinner said afterward. “He’s an incredible player and a good friend of mine… very, very unlucky from his side.”

The Italian, who had been battling a right elbow issue himself, was pushed to the brink as Dimitrov broke his serve early and dictated much of the match with aggressive shot-making.

Ultimately, Dimitrov’s body failed him again, a cruel blow for the Bulgarian who has withdrawn from his past four Grand Slams with injuries. He left the court to a standing ovation.

Sinner moves on to face American 10th seed Ben Shelton in the quarter-finals.