Sinner beats Auger-Aliassime at the U.S. Open and faces Alcaraz for a 3rd Grand Slam final in a row

Against Auger-Aliassime, Sinner was terrific in the opening set, merely so-so in the next. His run of 38 service holds that dated to the third round ended when Auger-Aliassime drove a 99 mph inside-out forehand winner for a break that he marked with a loud yell.

That forehand was key for the 25-year-old Canadian who was trying to reach his first major final and already had eliminated No. 3 Alexander Zverev, No. 8 Alex de Minaur and No. 15 Andrey Rublev.

When he closed that set with a 117 mph ace, Auger-Aliassime had grabbed 12 of 13 points and the match was all even.

After that set, Sinner left the court for medical attention and, while it wasn’t obvious what was going on, he looked just fine when he returned from the locker room. So did his play.

Later, he would say it was “nothing too bad” and “nothing serious,” without offering any specifics.

After managing only three winners, but six unforced errors, in the second set, Sinner was back to being Sinner in the third: 11 winners, four unforced errors. He broke thanks to a stumbling, awkward return of a 124 mph serve that somehow landed in, drawing a netted response from Auger-Aliassime.

More of that came in the fourth, when, after saving five break points early — he saved 9 of 10 throughout the evening — Sinner broke to move ahead 3-2. Just 25 minutes later, it was over, and Sinner had earned his 33rd win in his past 34 Grand Slam matches, which includes an unbeaten run of 27 on hard courts.