Novak Djokovic reached the third round of a Grand Slam for the 25th consecutive time while Serena Williams racked up her 80th US Open win as the top seeds eased into the third round.
They were joined in the last 32 by 2012 winner Andy Murray and reigning Wimbledon women's champion Petra Kvitova.
But former world number one Ana Ivanovic, the eighth seed, and 2011 champion Samantha Stosur were knocked out on a day when stiff winds brought new challenges at Flushing Meadows for players already tackling plus 30 degree heat (+90F).
World number one and top seed Djokovic breezed past France's Paul-Henri Mathieu 6-1, 6-3, 6-0, firing 13 aces and 33 winners as the 2011 champion comfortably remained on course for a fifth successive final appearance.
"It's very windy, but I managed to adjust to the conditions that obviously are not easy for myself and my opponent," said Djokovic, who next meets Sam Querrey of the United States, after his brief 90-minute appearance.
"I managed to play better in the important moments, play solid, use my serve efficiently with accuracy rather than speed."
World number one Williams, chasing a third successive New York title, her sixth in total and an 18th major, sent 25 winners past Vania King and broke serve six times, wrapping up a 6-1, 6-0 victory on windswept Arthur Ashe Stadium in just 56 minutes.
It was her second win over an American at the tournament this week after beating teenager Taylor Townsend and next she will face Varvara Lepchenko for a place in the last 16.
"It's so hard to play in the wind but I am happy to get through a solid match with the conditions," said the top seed whose colorful leopard print dress was as striking as her tennis.
"It wasn't easy, but you have to be able to adjust. I had fun out here, I enjoy playing out on Arthur Ashe court."
Eighth-seeded Murray brushed aside 27-year-old German qualifier Matthias Bachinger, the world number 235, with a convincing 6-3, 6-3, 6-4 win.
Murray exhibited none of the physical problems he suffered in the first round when he was cramping, sending down 36 winners past Bachinger, a contemporary from his junior days.
Canadian fifth seed Milos Raonic made the third round with a 7-6 (7/4), 5-7, 6-4, 7-6 (7/3) win over German qualifier Peter Gojowczyk on the back of 26 aces and 64 winners.
