Sharapova lights up US Open again with win over Ostapenko

Sharapova is now undefeated in 22 night matches at the Billie Jean King National Tennis Center.

"There's no doubt I feed off this energy," Sharapova said.

"We all spend so much time on the back courts with our teams practicing.

"When you get a chance to come out here why not give everything that you have."

After some shaky moments in her first two matches, Sharapova charged through the opening set, aided by 27 unforced errors from 2017 French Open champion Ostapenko.

Ostapenko cut that down in the second, but she couldn't halt five-time Grand Slam winner Sharapova, aiming to bounce back from a first-round loss at Wimbledon this year that was followed by injury withdrawals from tournaments in San Jose and Cincinnati.

Sharapova next faces Spain's Carla Suarez Navarro, who ousted sixth-seeded Caroline Garcia of France 5-7, 6-4, 7-6 (7/4).