(Photo credit: Geoff Burke-Imagn Images)

For the first time in four years, Felix Auger-Aliassime is back in a Grand Slam semifinal.

After making just one quarterfinal appearance in the prior 15 majors, the Canadian's underdog U.S. Open run continued with a 4-6, 7-6 (7), 7-5, 7-6 (4) win over eighth-seeded Alex de Minaur of Australia in the quarterfinals on Wednesday.

Next up for Auger-Aliassime is top seed and defending champion Jannik Sinner, who won an all-Italian matchup against No. 10 Lorenzo Musetti 6-1, 6-4, 6-2 late Wednesday night.

While Auger-Aliassime is not a true underdog as the No. 25 seed at this year's U.S. Open, he now has beaten three straight top-15 opponents in No. 3 Alexander Zverev, No. 15 Andrey Rublev and now No. 8 de Minaur. It's the first time he has defeated multiple players ranked in the top 20 of the ATP rankings in the same major.

He is through to just his second Grand Slam semi all time, last doing so in the 2021 U.S. Open semifinals when he lost to Daniil Medvedev in straight sets.

'It feels amazing. Four years ago ... It feels like more,' Auger-Aliassime, 25, said in his on-court interview. 'It was a tough couple of years, but it feels great to be back in the semifinals. It's been an amazing tournament so far. It's not over, there's some tennis to play and the biggest challenges are yet to come, but that's what I live for.'

Auger-Aliassime's serve led the way in his quarterfinal victory as he averaged 191 mph on his first serve and racked up 22 aces with 11 double faults. de Minaur also had 11 double faults but far fewer aces with eight in the match lasting four hours, 10 minutes.

de Minaur took the first set, breaking Auger-Aliassime at 3-3 and serving out from there with two service-game holds. It was a sloppy start for the Canadian, who had 15 unforced errors in the opening set and then 19 in the marathon 85-minute second set, which he won in an extended tiebreaker after defending one set point.

Auger-Aliassime cleaned up the mistakes down the stretch of the match with just 16 total unforced errors over the third and fourth sets. He finished the match with 51 winners to 50 unforced errors while de Minaur had notably more unforced errors (43) than winners (29).

In the third set, Auger-Aliassime was broken when serving for the set up 5-4, but broke back and then served out the set on his second attempt. In the fourth set, he rallied from down 4-1 to force another tiebreaker, and closed out the match by winning five of the final seven points.

'It was just a lot of nerves today during the whole match, it wasn't pretty at all times, but that's what Grand Slam matches are,' Auger-Aliassime said. 'Somedays you won't feel your best, but I was willing to dig deep and do everything I can to stand here right now.'

With this loss, de Minaur falls to 0-6 all-time in Grand Slam quarterfinals, including defeats in this round at five of the last seven majors.

Sinner is one win away from his fifth consecutive Grand Slam final appearance. This year, he won the Australian Open and Wimbledon while finishing as runner-up at the French Open. He is the first player born in 1990 or later to reach all four men's major semifinals in the same year, according to OptaAce.

He got past Musetti in exactly two hours by dominating at the key moments. Sinner broke Musetti's serve on five of six opportunities while saving all seven break points he faced. The four-time Grand Slam champion recorded 10 aces and won 91 percent of his first-serve points (42 of 46).

The match pitted two close friends against each other.

'We have to take the friendship away for the match and then, when we shake hands, it's everything fine,' Sinner said postmatch. 'From my point of view, it was a great performance. Very solid, especially starting very well in the match. ...

'It's a very special tournament. There's no better place to play, a night match here in the biggest stadium we have with an amazing crowd, so it means a lot to me.'

Musetti was looking to make his second Grand Slam semifinal appearance of the season, having reached the final four at the French Open.

Auger-Aliassime owns a 2-1 head-to-head advantage on Sinner, though the Italian won their most recent meeting 6-0, 6-2 last month in the quarterfinals at Cincinnati.

In the other semifinal, No. 2 seed Carlos Alcaraz of Spain will face No. 7 Novak Djokovic of Serbia on Friday after both won on Tuesday.

--Field Level Media