Roger Federer continued his bid for a record sixth US Open title with a comfortable second-round win over France's Benoit Paire.
The 37-year-old Swiss eased to a 7-5 6-4 6-4 victory in New York City in one hour 56 minutes.
Paire had not beaten the 20-time Grand Slam champion in six previous meetings and never looked like causing an upset.
Second seed Federer will play Australia's Nick Kyrgios in the third round.
Kyrgios won 4-6 7-6 (8-6) 6-3 6-0 against France's Pierre-Hugues Herbert, fighting back from a set and a break down after being talked to by chair umpire Mohamed Lahyani.
Federer once dominated the men's singles at Flushing Meadows, winning his five titles in a row between 2004 and 2008 in a run of 41 consecutive matches.
That success has slowed down in the past decade, with his only other final appearance ending in defeat by Novak Djokovic in 2015.
This year he says regaining the US Open title is one of his "bigger priorities".
Asked whether the Federer of 2009 would beat the Federer of 2018 at Flushing Meadows, the Swiss said: "I really hope that this guy would win today just because I feel like I've improved many things over the years.
"I'm a more complete player than I was back then."
Federer and sixth seed Djokovic, who is aiming for his third US Open title and 14th Grand Slam, are projected to meet in the quarter-finals this year.
Djokovic meets American Tennys Sandgren in the second round later on Thursday.
Frustration mounted for Paire as the match went on
While Federer was largely untroubled, there was a hint of danger in the first set which required him to dig deep to avoid any potential problems.
Federer let a break slip in the opening set as Paire fought back to level and then put the Swiss under pressure at 30-30 on his serve at 5-4, only for Federer to produce an accurate ace out wide for 40-30 on his way to a valuable hold.
Federer then broke in the next game when Paire produced a double fault on break point, enabling him to wrap up the set with a hold to love.
"It's important to stay with your opponent. The first set can be so crucial, so it was definitely key to the whole outcome," the Swiss said.
"I could play a bit freer, he got frustrated."
Frustration began to turn to anger for Paire, who smashed three racquets in an extraordinary tantrum in Washington last month, as Federer took his serve in the fifth game on the way to the second set.
From that point there was no way back for the Frenchman.