Defending champion Jannik Sinner has battled past 25th seed Felix Auger-Aliassime 6-1 3-6 6-3 6-4 in the US Open semi-finals to set up a blockbuster title clash with Carlos Alcaraz and renew one of the sport's most compelling rivalries.

Shortly after Alcaraz wove his magic to dismantle 24-times Grand Slam champion Novak Djokovic on Arthur Ashe Stadium on Saturday Hong Kong time, the usually machine-like Sinner misfired at times but prevailed to ensure a third successive major final with the Spaniard.

The Italian world No 1 – who is chasing a fifth career major after joining Rod Laver, Roger Federer and Novak Djokovic as the only men to reach all four Grand Slam finals in a season – faced brief resistance in the fifth game of the contest but dialled up the intensity to hold and wrapped up the lopsided opening set when Auger-Aliassime sent a backhand wide.

Auger-Aliassime settled his nerves in his second New York semi-final, breaking for a 5-3 lead in the next set en route to levelling the match, before going toe to toe with Sinner in the third set, only for the momentum to shift again.

Sinner, who took a medical timeout for an unspecified issue earlier, found his groove to close out the third set and staved off a strong challenge from his reinvigorated Canadian opponent with some clutch serving in the next set to advance.

In the earlier match, second seed Carlos Alcaraz took down 24-times major winner Novak Djokovic 6-4 7-6(4) 6-2 with clinical precision to reach the final, prevailing in a blockbuster showdown that packed the house at Arthur Ashe Stadium.

The match was billed as the hottest ticket in New York and lived up to the hype, with a scoreline that belied its intensity, as the 2022 champion Alcaraz soaked in deafening cheers on match point.

Djokovic had won their two most recent meetings, including in the quarter-finals of the Australian Open earlier this year, but the 38-year-old showed wear and tear against the Spaniard 16 years his junior.

"It's something that I'm working on, just the consistency on the matches, on the tournaments, on the year in general," said Alcaraz, who won his fifth major title at Roland Garros this year and finished runner-up at Wimbledon. "Just not having up and downs in the match. Just the level that I start the match, just wanted to keep that level really high during the whole match."

Djokovic dropped his serve when he sent a shot past the baseline in the opening game and was unable to set up a single break point chance in the first set, which Alcaraz closed out with an unreturnable serve.

Urged on by the celebrity-packed stands, the seventh seed got in the fight in the second set, sending over a superb backhand to convert on break point in the second game.

But Alcaraz had not dropped a set so far in New York and he put his foot on the gas, setting up a break point after surviving a 16-shot rally with one of his fine forehand winners and converting from the baseline.

Down 0-2 in the tiebreak, Djokovic outlasted his opponent in a cheeky exchange at the net and paused to take in the roars of the crowd, a reminder of the Serb's perennial appeal two decades after his Flushing Meadows main draw debut.

But the Spaniard kept his nerve, closing out the tiebreak with two more unreturnable serves before Djokovic gifted him a break point with a double fault in the fourth game of the third set.

The writing was on the wall for Djokovic as he hit another double fault on the penultimate point of the match, and he leaned on the net as he congratulated his opponent with a grin after handing over the contest with a wide forehand.

"Of course, it's frustrating on the court when you are not able to keep up with that level physically. But at the same time, it's something also expected," said Djokovic, who picked up the last of his four US Open titles in 2023. "It comes with time and with age." (Reuters)