Alexander Zverev reached the US Open quarter-finals with a straight-set victory over Jannik Sinner.
The German, who lost to Dominic Thiem in last year's final in New York, beat Italy's Sinner 6-4 6-4 7-6 (9-7).
Fourth seed Zverev saved five set points in the third as Sinner battled back, before sealing victory on his own serve in two hours 28 minutes.
He will face either home favourite Reilly Opelka or South Africa's Lloyd Harris for a semi-final spot.
Zverev is on a 15-match winning streak, having claimed the Cincinnati Open title in the lead-up to the US Open and Olympic gold in Tokyo.
He is one of the favourites to challenge world number one Novak Djokovic - who faces American wildcard Jenson Brooksby in the night session on Arthur Ashe - for the title.
Wimbledon finalist Matteo Berrettini is also in action on Monday against German qualifier Oscar Otte.