Australia's Nick Kyrgios has won the Citi Open after beating Japan's Yoshihito Nishioka 6-4 6-3 in the final.
The 27-year-old did not drop serve in the entire tournament.
He will return to the court on Monday to play alongside American Jack Sock in the men's doubles final.
He climbs from 63rd to 37th in the ATP rankings after his seventh career title.
The US Open begins on 29 August in New York.