SERENA Williams has taken just 65 minutes to beat Daria Gavrilova in the first round of the Cincinatti Open.

Williams was in ominous form just a fortnight out from the US Open, breaking the Australian's serve twice in each set in the 6-1 6-2 thumping.

The 23-time grand slam winner hit 27 winners and served eight aces to steamroll the world No.23 Gavrilova.

Williams bounced back from the most lopsided defeat of her career two weeks ago - a 6-1 6-0 loss to Johanna Konta in San Jose - to set up a meeting with Czech eighth seed Petra Kvitova in the second round.

Ajla Tomljanovic toughed out a three-set two-hour battle with Romanian Irina-Camelia Begu to advance to the round of 32.

The Australian qualifier won the important points when they mattered to secure a 4-6 6-3 6-3 victory.

World No.58 Tomljanovic will meet another Romanian in the next round in top-ranked Simona Halep, fresh off her title win at the Canadian Open.

Australian 16th seed Ashleigh Barty is scheduled to open her campaign against Czech wild card Marketa Vondrousova on Tuesday.

Wild card Victoria Azarenka, a two-time Australian Open champion, came from behind to beat Carla Suarez Navarro 6-7 (5-7) 6-2 6-4.

Madison Keys, the 13th seed, held off the challenge of fellow American Bethanie Mattek-Sands 3-6 7-6 (7-3) 6-4.

Tenth-seeded German Julia Goerges was trailing Frenchwoman Kristina Mladenovic 6-4 3-2 when she retired because of a lower left-leg injury.

Also through to the second round on Monday were wild card card Svetlana Kuznetsova, Aryna Sabalenka, Anett Kontaveit, Lesia Tsurenko and qualifier Viktoria Kuzmova.

Venus Williams withdrew from the event due to a right knee problem.