American Taylor Fritz earned his first berth in the final four of a major, beating No. 4 seed Alexander Zverev 7-6 (2), 3-6, 6-4, 7-6 (3) in the US Open quarterfinals Tuesday.

“I’ve had a lot of looks at quarterfinals over the last couple of years and today just felt different,” Fritz said. “I really felt like it was my time to take it a step further.”

It was the 12th-seeded Fritz’s fourth win over an ATP top-10 player in a major this season, the most by an American man in one year since Andre Agassi won five in 1999. Before this season, Fritz was 0-11 in majors against the ATP top 10.

Fritz beat Zverev, the 2020 US Open runner-up, in an epic five-setter at Wimbledon, and this time had the added boost of the home crowd being firmly on his side.

“I did nothing to deserve to win. It’s as simple as that,” said Zverev, who agreed when asked if this was the most frustrated he’s been after a match in a long time.

Fritz joined Frances Tiafoe (2022 US Open), Tommy Paul (2023 Australian Open) and Ben Shelton (2023 US Open) as the only active American men with major semifinal appearances.

Tiafoe could give the U.S. a second men’s semifinalist — and a guaranteed chance to play for the championship — when he faces No. 9 Grigor Dimitrov in the night session at Arthur Ashe Stadium.

If he wins, the No. 20-seeded Tiafoe would play Fritz, the highest-ranked American, in Friday’s semis.

“That could be crazy, so I guess we’ll see what happens,” Fritz said, “but either way I’ll be ready to go.”

The last men’s All-American matchup in the semifinals or later at a major was the 2005 US Open semifinals, when Agassi defeated Robby Ginepri in five sets.

There was little to separate Fritz and Zverev in the opening set as they traded blows from the baseline. But when the two towering players — Fritz is 6-foot-5, Zverev 6-foot-6 — approached the net, the New York crowd was treated to a mixture of drop shots and winners as the players second-guessed each other.

Zverev found himself 0-40 down while serving to stay in the set, but recovered to force an opening tiebreak. But Fritz was on the up, and as Zverev floundered with his forehand and desperately sought answers from his box, the American took the set with an emphatic overhead smash at the net.

Zverev bounced back in the second set with a different racquet, producing one of the shots of the tournament when he fired a return from out wide over the net post that curled back and landed on both the side and base lines, celebrating the point with his arms outstretched.

That put a spring in Zverev’s step and he broke at 4-3 before serving out the set to level the match, but Fritz returned the favor early in the third when he converted his first break point en route to a 3-0 lead.

Although Zverev clawed his way back, he was once again forced to save set points after some nervous errors, before Fritz finally took the third set when Zverev found the net as the crowd erupted.

With no breaks on offer in the fourth, Fritz got the upper hand in the tiebreak as Zverev once again faltered on crucial points before the American notched one of the biggest wins of his career.

Fritz controlled the action behind his strong serving, winning 20 of 21 points on his first serve in the fourth set and 81% in the match.

Zverev won 60% of his second serve points over the first two sets (12-of-20), but only 36% of those points over the final two sets (8-of-22).

He said he was also let down by his normally reliable backhand.

“I don’t remember since being on tour hitting my backhand this badly. I just don’t,” Zverev said. “I mean, I was missing shots which were in the middle of the court with no pace, and bottom of the net. Terrible. Just absolutely terrible by me.

“My forehand was OK, actually. My serve was OK. But my most reliable shot — the shot that I’m most known for, the shot that you normally wake me up at 3:00 a.m. and I would not miss — was absolutely not there today, and I have no words for it, to be honest.”

Zverev said Fritz played a good match and “absolutely deserved to win today.”

Fritz’s 16 major match wins are the most by an American man in a year since Andy Roddick, who was also the last American man to win a Grand Slam, 21 years ago at the US Open.

ESPN Stats & Information, The Associated Press and Reuters contributed to this report.