Cincinnati - Serena Williams re-established her customary superiority, hammering Daria Gavrilova 6-1, 6-2 to reach the second round of the Cincinnati Masters on Monday.
The 23-time Grand Slam champion showed full recovery in her first match since suffering the worst defeat of her career two weeks ago in San Jose when she was crushed 6-1, 6-0 in 51 minutes by British No 1 Johanna Konta.
But the 36-year-old was all business on Monday as she cleaned up on Australian Gavrilova, with Williams winning an 11th straight match here.
"I'm feeling pretty good tonight. It's never easy, no matter what the scoreline says," Williams said.
"I definitely felt relaxed after the first break, but you've got to keep going and try to go in for the whole thing."
Though she has not played the tournament in three years, Williams lifted back-to-back titles in 2014 and 2015 after losing the 2013 final to Victoria Azarenka.
Andy Murray's injury comeback was side-tracked as the three-time Grand Slam champion lost 6-1, 1-6, 6-4 to Lucas Pouille.
But fellow injury patient Stan Wawrinka opened with a defeat of 12th seed Diego Schwartzman 6-2, 4-6, 6-3.
Wimbledon champion Novak Djokovic survived a stiff test, needing nine match points to outlast Steve Johnson of the US 6-4, 7-6 (7/4). Djokovic is coming off a third round loss at last week's Toronto tournament.
Murray, returning from January hip surgery, was unable to get past the French 16th seed, hampering his preparations for the US Open starting on August 27.
"Physically, I felt okay. It's quick conditions here," Murray said.
"He was a little bit sharper than me out there.
"I maybe wasn't reacting as quickly to some shots I would have liked."
Murray last played 11 days ago in a Washington third-round match which took him three hours to win and ended at 03:00.
The 31-year-old two-time Wimbledon winner is working his way back slowly and felt he could not subject his body to a quarter-final just over 12 hours later, prompting him to withdraw from that event.
"After Washington, I took four, five days off the tennis court. I did a lot of training, a lot of rehab.
"As the year goes on, I'll be able to get a little bit more consistency like on the practice court and on the tennis court."
Pouille had lost his previous three matches to Murray, the last at Dubai in 2017.
Spanish 13th seed Pablo Carreno Busta started his week with a 6-3, 2-6, 6-3 defeat of France's Richard Gasquet, while Japan's Kei Nishikori put out Russian Andrey Rublev, 7-5, 6-3.
Peter Gojowczyk of Germany defeated Joao Sousa 2-6, 6-4, 7-5 and will next line up against seven-time winner Roger Federer, at second the highest seed in the field after the withdrawal of Rafael Nadal.
Canadian Denis Shapovalov beat US tournament debutant Frances Tiafoe 7-6 (8/6), 3-6, 7-5.
Sam Querrey beat ninth-seeded American compatriot John Isner 6-4, 6-7 (5/7), 7-6 (7/5).
In the women's first round, Azarenka made her first appearance here since 2015 count as she defeated Spanish veteran Carla Suarez Navarro 6-7 (5/7), 6-2, 6-4.
Double Grand Slam winner Svetlana Kuznetsova continued her 2017 injury comeback, beating Swiss Stefanie Voegele 6-4, 2-6, 7-6 (7/5).
US Open finalist Madison Keys, seeded 13th, defeated wild card Bethanie Mattek-Sands 3-6, 7-6 (7/3), 6-4; France's Kristina Mladenovic advanced when Julia Goerges retired hurt trailing 6-4, 3-2.
Results from the ATP and WTA Cincinnati Masters tournament on Monday (x denotes seeding):
Pablo Carreno Busta (ESP x13) bt Richard Gasquet (FRA) 6-3, 2-6, 6-3
Kei Nishikori (JPN) bt Andrey Rublev (RUS) 7-5, 6-3
Lucas Pouille (FRA x16) bt Andy Murray (GBR) 6-1, 1-6, 6-4
Peter Gojowczyk (GER) bt Joao Sousa (POR) 2-6, 6-4, 7-5
Denis Shapovalov (CAN) bt Frances Tiafoe (USA) 7-6 (8/6), 3-6, 7-5
Bradley Klahn (USA) bt Maximilian Marterer (GER) 7-6 (7/1), 6-4
Jérémy Chardy (FRA) bt Fernando Verdasco (ESP) 6-1, 6-2
Benoît Paire (FRA) bt David Ferrer (ESP) 6-2, 6-2
Leonardo Mayer (ARG) bt Michael Mmoh (USA) 6-4, 1-6, 6-4
Sam Querrey (USA) bt John Isner (USA x9) 6-4, 6-7 (5/7), 7-6 (7/5)
Novak Djokovic (SRB x10) bt Steve Johnson (USA) 6-4, 7-6 (7/4)
Stanislas Wawrinka (SUI) bt Diego Schwartzman (ARG x12) 6-2, 4-6, 6-3
Lesia Tsurenko (UKR) bt Danielle Collins (USA) 6-0, 6-2
Victoria Azarenka (BLR) bt Carla Suarez Navarro (ESP) 6-7 (5/7), 6-2, 6-4
Viktoria Kuzmova (SVK) bt Aliaksandra Sasnovich (BLR) 6-0, 4-6, 6-1
Svetlana Kuznetsova (RUS) bt Stefanie Voegele (SUI) 6-4, 2-6, 7-6 (7/5)
Anett Kontaveit (EST) bt Barbora Strycova (CZE) 6-3, 6-0
Madison Keys (USA x13) bt Bethanie Mattek-Sands (USA) 3-6, 7-6 (7/3), 6-4
Kristina Mladenovic (FRA) bt Julia Görges (GER x10) 6-4, 3-2 retired
Serena Williams (USA) bt Daria Gavrilova (AUS) 6-1, 6-2
Aryna Sabalenka (BLR) bt Johanna Konta (GBR) 4-6, 6-3, 6-4
Ajla Tomljanovic (AUS) bt Irina Begu (ROU) 4-6, 6-3, 6-3
Rebecca Peterson (SWE) bt Katerina Siniaková (CZE) 2-6, 6-4, 6-1
Alize Cornet (FRA) bt Jelena Ostapenko (LAT x11) 1-6, 7-5, 6-0