Carlos Alcaraz powered into the US Open semi-finals to set up a potential showdown with Novak Djokovic on Tuesday as Jessica Pegula punched her ticket to the last four.

Alcaraz needed just one hour and 56 minutes to seal a convincing 6-4, 6-2, 6-4 defeat of Czech 20th seed Jiri Lehecka on the Arthur Ashe Stadium court.

The Spanish second seed could now face a blockbuster semi-final against 24-time Grand Slam champion Djokovic, who takes on American fourth seed Taylor Fritz in Tuesday's other quarter-final.

Alcaraz could reclaim the world number one ranking with a victorious campaign in New York, a fact he is trying not to dwell on.

"Every time I step onto the court I try not to think about it," he said. "If I think about the number one spot too much I think I'm going to put pressure on myself and I don't want to do that."

Alcaraz has not dropped a set during a relentless march into the semi-finals and was once again in complete control against Lehecka.

The 22-year-old — who won the first of his five Grand Slam singles title at Flushing Meadows in 2022 — broke Lehecka in the opening game before wrapping up the first set with ease.

Alcaraz, efficient on his own serve in the first set, then raced away with the second set, breaking Lehecka to take a 5-2 lead before holding to take a 2-0 advantage.

The third set went with serve until the ninth game, when Lehecka smacked a straightforward forehand long at 30-40 down and was broken for the fourth time in the match. 

That left Alcaraz serving for the match, and he duly held to love, sealing his win with a scorching forehand into the corner.

Pegula eyes 'revenge'

In the women's draw on Tuesday, American fourth seed Pegula — beaten in the final last year — advanced to the semi-finals with a 6-3, 6-3 defeat of unseeded Czech Barbora Krejcikova.

Pegula entered the US Open on the back of a dismal run of form that had seen her make early exits at WTA tournaments in Washington, Montreal and Cincinnati.

But she has rediscovered her confidence while moving stealthily through the rounds at New York, albeit against a series of unseeded opponents.

"I think I've been playing some really good tennis," Pegula said after completing a 1hr 26min victory.

"It's crazy to feel this comfortable on the biggest court in the world with the craziest crowd and the best players. It's something that 10 years ago I never thought I'd be good at this but I guess I am."

Pegula will play reigning US Open champion Aryna Sabalenka or former Wimbledon winner Marketa Vondrousova on Thursday for a place in the final.

World number one Sabalenka, who defeated Pegula in last year's US Open final, faces Vondrousova in Tuesday's late women's quarter-final.

Pegula said she would welcome the chance to avenge last year's final defeat to Sabalenka.

"I think it would be cool to be able to get revenge, obviously," she said.