Aussie Open: Caroline Wozniacki, Angelique Kerber & Maria Sharapova through

Australian Open defending champion Caroline Wozniacki eased into the third round of the tournament with a straight-set win over Sweden's Johanna Larsson.

The third seed Wozniacki needed just 66 minutes to defeat world number 75 Larsson 6-1 6-3.

Wozniacki will face Maria Sharapova, who won the tournament in 2008, in the third round.

Sharapova, who has five Grand Slam titles, swept past Rebecca Peterson 6-2 6-1.

"That's a tough third round," said Sharapova. "There's no secret she loves playing out here. I've set up the challenge and I'll need to go out there and take it."

Three-time Grand Slam champion Angelique Kerber saw off Beatriz Haddad Maia 6-2 6-3.

The German, who won the Australian Open title in 2016, made just 10 unforced errors to the Brazilian's 39.

She will fancy her chances against wildcard Kimberly Birrell next after the world number 240 stunned 29th seed Donna Vekic.

The 20-year-old Australian beat Croatia's Vekic 6-4 4-6 6-1 to reach the third round of a Grand Slam for the first time.

Petra Kvitova, the two-time Wimbledon champion made quick work of her second-round match against Romania's Irina-Camelia Begu.

The Czech won 6-1 6-3 in 69 minutes and will face Switzerland's Belinda Bencic next.

The 2017 US Open winner, Sloane Stephens, set up a third-round meeting with Petra Martic after defeating Timea Babos 6-3 6-1.

Ninth seed Kiki Bertens suffered a surprise defeat to world number 42 Anastasia Pavlyuchenkova, despite the Dutch player taking the first set.

Russian Pavlyuchenkova, a quarter-finalist in Melbourne two years ago, won 3-6 6-3 6-3.

Australian Ashleigh Barty impressed the home crowd on Rod Laver Arena as the 15th seed saw off China's Yafan Wang 6-2 6-3 in little over an hour.

"I feel great," said Barty. "It's certainly nice to be playing in Australia and playing well."