NEW YORK -- Felix Auger-Aliassime got past No. 8 Alex De Minaur 4-6, 7-6 (7), 7-5, 7-6 (4) at the US Open across 4 hours, 10 minutes, Wednesday to reach his second Grand Slam semifinal -- and second at Flushing Meadows.
No. 25-seeded Auger-Aliassime's only other trip to the final four at a major came in New York in 2021 at age 21.
"Four years ago. It feels like more," said Auger-Aliassime, who advanced back then when Carlos Alcaraz stopped playing in the quarterfinals with an injured leg muscle. "It was a tough couple of years."
With his wins over No. 3 Alexander Zverev in the third round, No. 15 Andrey Rublev in the fourth and now De Minaur in the quarterfinals, this is the first time Auger-Aliassime has eliminated multiple ATP top-20 players during a single major.
The 25-year-old Canadian is guaranteed to face another player ranked that high Friday for a berth in the championship match -- either world No. 1 Jannik Sinner or No. 10 Lorenzo Musetti. No. 2 Alcaraz faces No. 7 Novak Djokovic in the other semifinal.
"It's not over. There's still some tennis to play, and the biggest challenges are yet to come," Auger-Aliassime said. "That's what I live for. That's what I train for."
He hit 22 aces and finished with a total of 51 winners to 29 for De Minaur, a 26-year-old Australian.
Auger-Aliassime was one point from trailing two sets to none when De Minaur led 6-5 in the second-set tiebreaker. But Auger-Aliassime erased that set point with a 120 mph ace. That began a run in which he grabbed four of five points to even the contest at a set apiece.
"Just a lot of nerves today, during the whole match. It wasn't pretty at all times," Auger-Aliassime said during his on-court interview in Arthur Ashe Stadium. "I was willing to dig really deep and do everything I can to stand here, right now."
Auger-Aliassime improved to 6-0 in tiebreaks at this year's US Open, tied for the most won by any man en route to the semifinals since tiebreaks were introduced at the 1970 tournament.
De Minaur dropped to 0-5 in major quarterfinals -- the only men in the Open era with a worse record in the quarterfinals of a Slam are Rublev (0-10) and Tommy Robredo (0-7). Guy Forget was also 0-5 for his career.
"I feel like this one was on my racket, and it is a shame," De Minaur said. "I don't know how I'll handle it. I'm definitely, as of right now, seeing red, but yeah, I'll get over it. It's just tennis, right?"
ESPN Research and The Associated Press contributed to this report.