Dimitrov was playing fantastic tennis, running Sinner around the court and delivering booming serves. Dimitrov won the first set 6-3 and survived a hard-charging comeback attempt from the Italian in the second to take the set 7-5 and put the world No. 1 in a desperate position.

After winning the first two sets and having Sinner in serious upset danger, Grigor Dimitrov had to retire due to injury in the third set. The 34-year-old from Bulgaria had battled injuries for much of his career, and he knew something was wrong with his pectoral muscle after a serve.

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.