Jannik Sinner advanced to the Wimbledon quarterfinals despite hurting his right elbow in a fall in the opening game and dropping the first two sets Monday night, when his opponent, Grigor Dimitrov, wound up quitting in the third because of an injured pectoral muscle.

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.

The top-seeded Italian, dealing with an apparent arm injury, had dropped the first two sets to Grigor Dimitrov before the Bulgarian was forced to retire because of injury.