MASON, Ohio (AP) -- Serena Williams bounced back from the most lopsided loss of her career, cruising past Darla Gavrilova 6-1, 6-2 at the Western & Southern Open on Monday.
Williams, a 23-time Grand Slam winner and a former champion in Cincinnati, needed just 65 minutes to dispatch Gavrilova. She'll face eighth-seeded Petra Kvitova in Tuesday's second round.
Williams lost to Johanna Konta 6-1, 6-0 in San Jose, California, before withdrawing from last week's Rogers Cup in Montreal.
Earlier Monday, Andy Murray lost to Lucas Pouille 6-1, 1-6, 6-4, clearing another obstacle for Roger Federer in this U.S. Open tuneup.
Top-seeded Rafael Nadal dropped out Sunday night to prepare for the U.S. Open after winning his fifth title of the year in Toronto.
Murray had his best result since missing 11 months following hip surgery when he reached the quarterfinals in Washington two weeks ago. But he had a hard time adjusting to the Cincinnati courts.
"The start of the match was not good," he said. "It was a pretty bad first set. After that, it was a little better."
Federer, seeded second, has won in Cincinnati a record seven times but hasn't played here since winning in 2015. In 2016, he had a knee injury, and in 2017 he had back problems.
"Cincinnati has always been a good tournament for me," said Federer, the reigning Australian Open champion. "I was sad not to play here last year, and two years ago there wasn't a chance. I'm glad to be back."
Even with the top-ranked Nadal missing, Federer liked the strength of this field, especially with Murray and Wimbledon champion Novak Djokovic having recovered from injuries.
"That's why you have such a good, exciting draw," Federer said before Murray's match was over. "It's a pity Rafa isn't playing. He would have added massively to that part of the draw."
Grigor Dmitrov, the defending champion who is seeded fifth, was not entirely upset about Nadal's absence.
"When Rafa is missing, he's missed, not so much by the players as much as the fans," he said. "All joking aside, I love spending time with Rafa and practicing with him and playing with him. I would be the last person to say I wouldn't want to play with him."
Monday's first full day of main-draw competition opened with 13th-seeded Madison Keys holding off Bethanie Mattek-Sands 3-6, 7-6 (3), 6-4 to reach the second round. Wild-card Victoria Azarenka, a two-time Australian Open champion, also came from behind to beat Carla Suarez Navarro 6-7 (5), 6-2, 6-4.
Tenth-seeded Julia Goerges was losing to Kristina Mladenovic 6-4, 3-2 when she retired because of a lower left leg injury. Advancing were qualifier Ajia Tomjanovic, Aryna Sabalenka, Lesia Tsurenko, wild card Svetlana Kuznetsova, qualifier Viktoria Kuzmova and Anett Kontaveit.
On the men's side, Sam Querrey ground out a 6-4, 6-7 (5), 7-6 (5) win over fellow American and ninth-seeded John Isner. Querrey gained an edge with a mini-break on the fifth point of the second tiebreaker when Isner sailed a forehand wide of the backhand sideline. Querry closed out the 2-hour, 7-minute match with an ace that survived a challenge by Isner.
Kei Nishikori beat Andrey Rublev 7-5, 6-3, and 13th-seeded Pablo Carreno Busta topped Richard Gasquet 6-3, 2-6, 6-3. Other winners were Leonardo Mayer, Jeremy Chardy, Benoit Paire, Peter Gojowczyk, Denis Shapovalov and qualifier Bradley Klahn.