British number one Johanna Konta earned her first competitive victory since the WTA Tour restarted with a confident win over Belgium's Kirsten Flipkens at the Western and Southern Open in New York.
Konta, seeded eighth and given a first-round bye, took the final 11 games to win 6-2 6-0 and reach the third round.
However, Dan Evans lost to Canada's Milos Raonic in his second-round match.
The British number one, 30, struggled to cope with his opponent's big serving in a 6-3 7-5 defeat.
Former world number one Andy Murray, 33, will face a stern test of his fitness and playing levels when he takes on Germany's world number seven Alexander Zverev later on Monday (about 20:00 BST).
The tournament is usually held in Cincinnati but has been moved to Flushing Meadows to create a two-tournament safety bubble that also incorporates next week's US Open.
Konta, 29, produced a dominant performance in her first match since a straight-set defeat at the Lexington Open two weeks ago, where she felt light-headed after suffering from heart palpitations.
Afterwards Konta said was not overly worried about the issue and she experienced no physical problems in the New York heat against Flipkens.
From the start, Konta put her opponent's serve under pressure and broke twice in a five-game winning streak to clinch the opening set.
She continued to strike the ball superbly in the second set, dropping just seven points as she overwhelmed 78th-ranked Flipkens in a 24-minute set.