Alexander Zverev is leading 6-2 6-4 4-6 against Dominic Thiem in the US Open men's singles final.
Both players are looking for a maiden Grand Slam title.
Second seed Thiem is appearing in his fourth major final, while fifth seed Zverev is in his first final.
The final is being played behind closed doors on Arthur Ashe Stadium at Flushing Meadows, New York.
