San Francisco Frontiers - Tiafoe sets up all-American US Open semi-final

Tiafoe, the 20th seed, progressed after ninth-ranked Grigor Dimitrov suffered an injury in the third set of their quarter-final and quit in the fourth with the score at 6-3, 6-7 (5/7), 6-3, 4-1.

Tiafoe also made the semi-finals in 2022 while Fritz reached his first Grand Slam last-four by earlier defeating 2020 runner-up and fourth-ranked Alexander Zverev 7-6 (7/2), 3-6, 6-4, 7-6 (7/3).

Dimitrov, 33, playing in his first US Open semi-final since 2019, hurt himself in the third set before leaving the court to seek treatment.

The Bulgarian returned in a desperate attempt to continue the match but was reduced to walking pace as his hopes slipped away.

"It's not the way I wanted to win even if I'm happy to get through to the semi-finals," said Tiafoe.

"It was a very high-level match. You're going to see me against another American, it's going to be great. It will be the biggest match of our careers, we've known each other since we were 14."

Andy Roddick was the last American man to win a Grand Slam title when he claimed the 2003 US Open.

He was also the last home player to make a final in New York when he was defeated by Roger Federer in the 2006 championship match.

Friday's semi-final between Tiafoe and Fritz will be the first all-American men's singles last-four clash since Andre Agassi defeated Robby Ginepri at the 2005 US Open.

Tiafoe broke Dimitrov for a 3-2 lead in the first set before sealing it on a fourth set point.

The American stretched to a 3-1 advantage in the second before Dimitrov clawed his way back in the seventh game.

In a bizarre conclusion to the set, Dimitrov served double faults on two of his three set points.

Tiafoe then mirrored his rival, double-faulting on the third to square the quarter-final at a set apiece.

That was as good as it got for Dimitrov whose challenge fizzled out once he was injured in the third.

P.Adams--SFF