NEW YORK - Spaniard Carlos Alcaraz beat 2014 champion Marin Cilic 6-4, 3-6, 6-4, 4-6, 6-3 at the US Open on Monday to set up a "next-generation" quarter-final clash against Jannik Sinner.

After battling for 3hr 53min at Arthur Ashe Stadium, where the roof was closed due to rain, Alcaraz, 19, dropped to his knees in jubilation after sealing the contest on his first match point when Cilic's return hit the net.

The sizeable crowd on the main show court gave the players a standing ovation with the clock striking 2.24am (2.24pm Singapore time) , a couple of minutes short of the latest-ever finish at the New York Grand Slam.

Alcaraz's victory over the 15th-seeded Croat ensured there will be a new men's Grand Slam champion on Sunday and also kept the Spaniard in contention to become the youngest world No. 1 when the ATP rankings are updated after the final.

The third seed will next meet 21-year-old Italian Sinner, seeded 11th, for a maiden Grand Slam semi-final spot. REUTERS