Great Britain's Andy Murray beat America's Frances Tiafoe in three sets in the Western & Southern Open first round at Flushing Meadows.
Two-time champion Murray won 7-6 (8-6) 3-6 6-1 in his first match of the year to set up a meeting with German fifth seed Alexander Zverev.
The tournament is a warm-up for the US Open at the same venue from 31 August.
In the women's draw, American Coco Gauff lost in straight sets to Maria Sakkari in the opening round.
Greece's Sakkari, 25, took one hour and five minutes to beat the 16-year-old, who reached the last four at the Top Seed Open in Kentucky last week, 6-1 6-3.