Los Angeles - Five-time Grand Slam champion Maria Sharapova made a battling return to US hardcourts on Monday with a 6-1, 4-6, 6-0 victory over American Jennifer Brady in Stanford, California.

"I feel like I just want to hug everyone and say thank you," Sharapova told fans in a post-match interview. "It's my first match in the States in a really long time, and it's the closest thing to home for me."

The former world number one from Russia hadn't played in the US since March of 2015, before serving a 15-month doping suspension for the use of meldonium. She returned to competition in April, but her comeback has been disrupted by a hip injury that forced her to withdraw from Wimbledon qualifying. Sharapova, whose ranking has fallen to 171 in the world, received a wild card into the premier level tournament in Stanford, where she was tested Monday by the 80th-ranked Brady. Sharapova got off to a brisk start. Although she needed to save three break points in the sixth game to take a 5-1 lead in the opening set, she broke in the next game to seize the set before Brady won the second.

"I had a bit of a letdown but that's the way it is," Sharapova said. "You finish a set and think you've got it, but she came out firing, capable of hitting winners and big serves."

Early in the third Sharapova fought off two break points to consolidate her lead, and wrapped up the match after two hours and two minutes. "I feel like I face a lot of things: not competing for a long time, an opponent who's able to play some great tennis ... I feel like I'm playing catch-up against everyone who's had a head start," Sharapova said. "All that matters is that I keep playing."

Sharapova, who has also accepted a wildcard into the WTA tournament in Cincinnati -- another key warmup for the US Open -- booked a second-round meeting with seventh-seeded Ukrainian Lesia Tsurenko, a 6-3, 6-3 winner over Spain's Lara Arruabarrena.

Wimbledon champion Garbine Muguruza, who stunned Venus Williams in the final at the All England Club, is the top seed. She will open with a second-round match against American Kayla Day, who defeated Japan's Misaki Doi 6-4, 6-2 on Monday.

US Open prep heats up for No 2 Halep

Second-ranked Simona Halep has the longest current run in the world top 10, reached her second career Grand Slam final in June and defends a title next week in Toronto.

But the 25-year-old Romanian is looking for the big prize that has eluded her, a Grand Slam title, as she begins working to the US Open at this week's WTA and ATP Citi Open. Halep is getting an early jump on US Open preparations at the Washington hardcourt event, becoming the highest-ranked player ever in the field after she said this week's WTA event in Stanford denied her a wildcard entry.

"I want to be in my best form at the US Open," Halep said. "This tournament is very important. Every match is tough and important for my level. I'm focused on what I have to do on the court and what I need to do to get my game strong."

Halep reached her first Grand Slam final in 2014 at Roland Garros, falling to Russia's Maria Sharapova, then made it back to the French Open final this year only to fall again, up a set and 3-0 before squandering the lead and falling to Latvia's Jelena Ostapenko.

She followed with a quarter-final exit at Wimbledon and after a title defense next week in Canada hopes to improve upon her best US Open result, a 2015 semi-final run. "I'm still confident," Halep said. "But now it's a different season. I expect some tough matches. I'm ready. I want some matches." Halep's first match will be Tuesday against another competition-hungry wildcard, American Sloane Stephens, who missed 11 months after left foot surgery before returning at Wimbledon. Stephens won her first WTA title at Washington in 2015.

On the men's side, five of the top 11 players in the world will take part, including four past champions who won titles in their last Washington appearances -- Argentina's Juan Martin Del Potro, Canada's 10th-ranked Milos Raonic, Japan's ninth-ranked Kei Nishikori and defending champion Gael Monfils of France.

"The high level of players make this a very important tournament," Del Potro said. "It's going to be a very tough tournament." Austrian Dominic Thiem, ranked seventh, is the men's top seed with 20-year-old German Alexander Zverev seeded second and moving Monday into a career-best world number eighth level.

"Of course it's nice to be top seed here but it doesn't affect anything because the guys behind me are really strong. It's a really strong field," Thiem said. "It's going to be tricky first rounds for everybody." US ninth seed John Isner, a three-time Washington runner-up, withdrew Monday with a sore right knee.

He won ATP titles the past two weeks at Newport and Atlanta. South African-born Australian Marc Polmans was the qualifying lucky loser who replaced Isner in the draw with a first-round bye.

Isner jumped past Jack Sock to once again become the US number one, reaching 18th in the rankings to 19th for Sock, who could have faced Isner in the third round.