Frances Tiafoe now leads his head-to-head with Andrey Rublev 2-1Venue: Flushing Meadows, New York Dates: 29 August-11 SeptemberCoverage: Daily radio commentaries across BBC Sounds and the BBC Sport website and app, with selected live text commentaries and match reports on the website and appFrances Tiafoe reached a maiden Grand Slam semi-final by dispatching Andrey Rublev in straight sets in front of a home crowd at the US Open.
The 24-year-old American beat the Russian ninth seed 7-6 (7-3) 7-6 (7-0) 6-4 in New York.
Tiafoe, who stunned Rafael Nadal in the previous round, will play Spain's Carlos Alcaraz or Italian Jannik Sinner in the last four.
They meet in the final men's singles quarter-final (around 01:30 BST).
"This is wild, this is crazy. I had the biggest win of my life 48 hours ago. To back it up, it's tough to turn the page, but I did, and now I'm in the semis," said Tiafoe, who is the first American man to reach the US Open semi-finals since Andy Roddick in 2006.
"I feel so at home on courts like this. This court is unbelievable.
"I always find a way somehow on this court. Let's enjoy this one but we got two more."
World number 11 Rublev, who has now played in six major quarter-finals without progression, looked the more dangerous in the early stages of his third meeting with Tiafoe and was the first to threaten with two break points in the sixth game of the opening set.
Although those were saved, he continued to press Tiafoe but, after saving a break point himself, failed to convert a set point opportunity as the American took the opener into a tie-break.
From there, and in front of a partisan crowd, Tiafoe took control, sealing the first set with an ace on his second set point.
Like the first, the second set went all the way on serve, but if cracks were beginning to show in Rublev's composure, they shattered in the tie-break.
A composed Tiafoe - who has not lost a tie-break so far in the tournament - dominated from the off, Rublev's anger boiling over as he repeatedly smashed his racquet against his own knee, his emotion heightened as Tiafoe conducted the Arthur Ashe crowd at 6-0 up before wrapping up the tie-break bagel.
At last, the third set brought the first break of serve in normal play as Rublev was left in tears after allowing Tiafoe to edge ahead. It was third time lucky for the 22nd seed after he had seen two break points saved four games earlier.
Tiafoe then withstood a tricky next game, forced to save two break points with one of his 18 aces, before going on to serve out the match with the last of those and become the first black American man to reach the last four of the tournament since Arthur Ashe in 1972.
Victory ensures he will enter the world's top 20 for the first time when the rankings are published next week.
