Maria Sharapova made a winning return from injury in the Bank of the West Classic on Monday night.
The former world number one, a wild card in the event at Stanford, California, defeated Jennifer Brady 6-1 4-6 6-0.
Sharapova, struggling with a thigh problem recently, got an early break of serve and did not look back in the opening set.
Although her American opponent won the second set to level the match, Sharapova broke early in the third and maintained control to win in two hours and two minutes.
The Russian will face Lesia Tsurenko in the second round, after the Ukrainian overcame Lara Arruabarrena 6-3 6-3.
Elsewhere, Kayla Day beat Misaki Doi 6-4 6-2 to set up a second-round match with top seed Garbine Muguruza - the beneficiary of a first-round bye.
Natalia Vikhlyantseva defeated Danielle Lao 6-4 6-3 and will face Ana Konjuh in the second round, after her opponent Maria Erakovic retired while trailing 6-3 1-0.
Nicole Gibbs battled from a set down to get past fellow American Claire Liu 4-6-6-2 7-6 (7/5) in the late match.
In the Citi Open in Washington, there were first-round wins for Andrea Petkovic, Bianca Andreescu, Julia Goerges, Alison Van Uytvanck, Sara Errani, Oceane Dodin, Aryna Sabalenka and Mariana Duque-Marino.