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.

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.

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.