Grigor Dimitrov made an assured start to his US Open with a 6-1 6-4 6-2 win over Czech qualifier Vaclav Safranek wednesday.
The 26-year-old seventh seed, who won the Cincinnati title earlier this month without dropping a set, advanced in an hour and 48 minutes.
Austria’s Dominic Thiem made short work of Alex de Minaur in their rain-delayed match, securing a 6-4 6-1 6-1 victory.
The sixth seed resumed 1-0 up in the third set on Wednesday and took less than half an hour to complete his win.
Thiem will play either Cypriot veteran Marcos Baghdatis or American 20-year-old Taylor Fritz in the second round.
Elsewhere, French 26th seed Richard Gasquet, who reached the semi-finals at the US Open in 2013, lost 3-6 6-2 6-4 6-2 to world number 59 Leonardo Mayer.
Tomas Berdych ensured there would be no repeat of home-crowd favourite Ryan Harrison’s 2016 heroics.
American Harrison beat sixth seed Milos Raonic on his way to the third round at Flushing Meadows last year, but was swept aside 6-4 6-2 7-6 (7-4) by the Czech 15th seed.
Gael Monfils won the all-French contest on Court 17, seeing off compatriot Jeremy Chardy 7-6 (8-6) 6-3 6-4 to set up a second-round meeting with Donald Young.
Ukrainian Alexandr Dolgopolov, whose defeat by world number 114 Thiago Monteiro earlier this month is being investigated by the sport’s integrity unit, beat Germany’s Jan-Lennard Struff after retirements in the first round in 2015 and 2016 at the US Open.