Carlos Alcaraz battled past Jannik Sinner in five sets on Thursday to set up a US Open semifinal clash against Frances Tiafoe.

In the women’s draw, Iga Swiatek and Aryna Sabalenka on Wednesday set up a semifinal clash after straight sets wins in their respective quarterfinal matches.

A thrilling 5hr 15min duel that finished at 2:50am local time — the latest ever finish in the tournament’s 141-year history — ended with the 19-year-old Alcaraz claiming a 6-3, 6-7 (7), 6-7 (0), 7-5, 6-3 victory.

In the earlier men’s singles quarterfinal, Tiafoe, aiming to become the first African-American man to win the US Open since Arthur Ashe in 1968, put on a scintillating performance to defeat Russian ninth seed Andrey Rublev 7-6 (3), 7-6 (0), 6-4 in 2hr 36min.

It was another superb giant-killing performance from the 24-year-old Tiafoe, who eliminated Spanish legend Rafael Nadal in the fourth round on Monday.

Tiafoe, the son of immigrants from Sierra Leone who began playing tennis as a four-year-old when his father worked as a live-in caretaker at a tennis facility in Maryland, said he had drawn inspiration from the raucous home crowd in Arthur Ashe Stadium.

Tiafoe’s victory was founded on a rock-solid service game and a mastery of the key moments.

The American hammered down 18 aces and was never broken once against Rublev, who was aiming to reach his first Grand Slam semifinal after five previous quarterfinal exits.

Tiafoe showed the greater composure as he won the first two sets via tiebreakers, leaving Rublev with a mountain to climb.

The Russian did well to hold serve in the third game of the third set, recovering from 15-40 down.

Yet Tiafoe grabbed a break for a crucial 4-3 lead soon afterwards that left Rublev overcome with emotion, appearing to sob into his towel.

Tiafoe held off two break points in the next game and took a 5-3 lead with his 17th ace before closing out the win.

Swiatek into third Major semi of 2022

Swiatek reached her third Grand Slam semifinal of 2022 and first at the US Open with an error-strewn triumph over Jessica Pegula, the last remaining American woman in the tournament.

French Open champion Swiatek claimed a 6-3, 7-6 (4) win, her third against Pegula this year.

World No 6 Sabalenka made the last-four for a second successive year with a 6-1, 7-6 (4) victory over former finalist Karolina Pliskova.

Swiatek has got the better of Sabalenka on three occasions this season on the way to her titles in Doha, Stuttgart and Rome.

On Wednesday, she came through a mistake-plagued quarterfinal which featured 13 breaks of serve and a combined 61 unforced errors.

Swiatek overcame giving up the first break of the match in the fifth game to reel off 16 of the next 18 points to claim the opening set in 38 minutes.

The pair exchanged three service breaks apiece in the first eight games in an untidy second set.

It was the French Open champion who carved out the seventh break on a net cord to give herself the opportunity to serve for the match.

Eighth-ranked Pegula roused herself to stay alive before a double fault on break point in the 11th game handed Swiatek a second opportunity to seal a spot in the semifinals.

The top seed failed again as Pegula grabbed the 10th break to send the set into a tiebreak which the Pole dominated.

Sabalenka reached the semifinals for a second successive year, fired up by the lingering and bitter aftertaste of her Wimbledon ban.

Russian and Belarusian players, such as Sabalenka, were prevented from competing at the All England Club due to the invasion of Ukraine. Belarusian players were banned from Wimbledon because Belarus is a close ally of Russia and has allowed Moscow to use its territory to launch attacks into Ukraine.

The ban deprived Belarus’s Sabalenka of the opportunity to improve on her semifinal run in 2021.

She admitted that she made a determined effort not to watch any of this year’s grass-court Grand Slam as she trained in Miami during her enforced break from the sport.

The 24-year-old Sabalenka fired seven aces and a total of 30 winners past Pliskova, the 2016 runner-up in New York, without facing a break point.

Sabalenka is making the most of her great escape in the second round in New York when she saved two match points against Kaia Kanepi having been a set and 1-5 down.

On Wednesday, she raced through the first set in just 28 minutes on the back of three service breaks.

The 30-year-old Pliskova managed just a single winner in the opener while serving up five double faults.

Czech World No 22 Pliskova saved two break points in the eighth game of the second set but was unable to halt Sabalenka’s powerful drive to the last four.

US Open results on Wednesday (x denotes seed; players representing Russia and Belarus are banned from competing under the name or flag of their countries)

Men’s singles Quarter-finals

Carlos Alcaraz (ESP x3) bt Jannik Sinner (ITA x11) 6-3, 6-7 (7/9), 6-7 (0/7), 7-5, 6-3

Frances Tiafoe (USA x22) bt Andrey Rublev (x9) 7-6 (7/3), 7-6 (7/0), 6-4

Women’s singles Quarter-finals

Iga Swiatek (POL x1) bt Jessica Pegula (USA x8) 6-3, 7-6 (7/4)

Aryna Sabalenka (x6) bt Karolina Pliskova (CZE x22) 6-1, 7-6 (7/4)