– Roger Federer says his favorite drinks are cold water and a sparkling glass of champagne. Both could be on tap at the U.S. Open: Federer needed a few swigs of water on another steamy day at the Open and he played like a former champion set to uncork a celebratory bottle of bubbly.

Federer’s coolness on the court belied another day where players needed cooling towels as much as their rackets. Federer, a five-time U.S. Open champion, had steeled himself for the heat by changing up his routine — he made an early trip to New York to prep his game in the sweltering sun.

Federer was crisp in a 7-5, 6-4, 6-4 win over Benoit Paire in and made it 18 of 18 lifetime in the second round of the U.S. Open. Up next, Federer plays No. 30 seed Nick Kyrgios who, after a curious and lengthy intervention from the chair umpire, came back to beat Pierre-Hugues Herbert 4-6, 7-6 (6), 6-3, 6-0.

“If you train in the cold all the time, all of a sudden it hits you, the humidity and heat,” Federer said. “I don’t care how fit you are, what you’re used to, the humidity can really get to you. I think that was a good choice.”

Three seeded men fell, with No. 12 Pablo Carreno-Busta stopping in the fifth set of his match with a leg injury, while No. 14 Fabio Fognini lost to John Millman 6-1, 4-6, 6-4, 6-1 and No. 23 Hyeon Chung lost to Mikhail Kukushkin 7-6 (5), 6-2, 6-3.

Angelique Kerber, the 201`6 champion, 2017 runner-up Madison Keys and two-time Wimbledon champ Petra Kvitova all won.