Sinner, the reigning US Open champion and ranked number one in the world, won the quarterfinal relatively easily: 6–1, 6–4, 6–2.
This was the tournament's first all-Italian quarterfinal.
We had to put the friendship aside for the match, but when we shook hands, everything was fine again, says Sinner.
He only needed two hours to secure a spot in the semifinals – the first set took only 27 minutes.
It was a fantastic performance, very stable. I started the match very well.
Sinner has only lost 38 games in his five matches.
Musetti, on the other hand, was chasing his first semifinal in the US Open after reaching the semifinals in the French Championships this year and in Wimbledon last year. But he had a terrible start against his Davis Cup teammate, fell behind 5–0 and won only nine points in total against Sinner's 25 in the first set.
Musetti got more chances against Sinner's serve as the game progressed, but never really got the opportunity to turn the match around.
Sinner has already won two Grand Slam titles this year – the Australian Open and Wimbledon. In the French Championships, he lost the final to the Spaniard Carlos Alcaraz.
In the semifinals, he will face Canadian Felix Auger-Aliassime, who earlier on Wednesday knocked out Australia's Alex de Minaur.
