Five-time US Open champion Roger Federer cruised into the second-round thanks to a comfortable 6-3 6-2 7-5 win over Slovenia's Grega Zemlja.
In a match which was postponed from the night before because of rain, the Swiss star, making his 56th Grand Slam start in a row looked in supreme form on Arthur Ashe Court.
Federer, who is seeded seventh at Flushing Meadows - his lowest ranking for over a decade - fired 12 aces and 35 winners past the 62nd-ranked Zemlja.
The 32-year-old 17-time major champion won 20 of 21 points at the net to advance in 93 minutes.
"I felt great," Federer said. "Day session or night session it doesn't really matter when you play on Arthur Ashe Court."
He will next tackle Argentina's Carlos Berlocq for a place in the last 32.
Meanwhile, Frenchman Jeremy Chardy knocked out Federer's conqueror at Wimbledon, Sergiy Stakhovsky from Ukraine in a five sets, 6-4 4-6 6-2 4-6 6-4.
Fifth-seeded Tomas Berdych breezed past Italy's Paolo Lorenzi 6-1 6-4 6-1, and 12th seed Tommy Haas defeated Paul-Henri Mathieu 6-4 6-4 6-1 to set up a date with Yen-Hsun Lu from Chinese Taipei.
In another five-set thriller, Brazilian Rogerio Dutra Silva overcame Vasek Pospisil from Canada 4-6 3-6 7-6 (9) 6-2 7-6 (10).
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