In a video of the moment, it looked as though the 34-year-old Dimitrov injured a pectoral muscle on a volley. Almost immediately after the hit, he fell to the ground, clutching the right side of his chest in pain.

Dimitrov & Jannik Sinner share an embrace as Grigor retires from their match at Wimbledon due to injury Grigor has had to deal with so much over the last few years Hard to watch this happen to anyone, especially someone as kind & hardworking as him 💔 pic.twitter.com/2k7gXAxgDq

THE ALL ENGLAND CLUB, LONDON — World No. 1 Jannik Sinner was on the precipice of a fourth-round exit from Wimbledon when he ended up on the receiving end of the absolute worst kind of good luck in sports.