Gavrilova, Serena winners in Indian Wells

Serena Williams battled hard for victory over Kiki Bertens at Indian Wells

Daria Gavrilova is through to the third round of the WTA tournament in Indian Wells after a straight-sets victory over Yanina Wickmayer.

The Australian toughed it out in a first set tiebreaker before easing to a 7-6 (7-3) 6-2 victory.

The 26th-seeded Gavrilova is the lone Aussie remaining in the main draw after Ashleigh Barty and Samantha Stosur suffered second-round losses on Friday.

Serena Williams continued her comeback with a battling 7-6 (7-5) 7-5 win over world No.29 Kiki Bertens, to set up a third-round encounter with her sister Venus.

Serena, who is returning to the sport after taking more than a year away for the birth of her first child, was ragged at times but used her power to wear down her Dutch opponent.

"She started out really strong," the 23-time grand slam champion Williams said in a courtside interview.

"I was (thinking) I've just got to keep going and do the best I can.

"I'm just happy to be out here. Everything is a bonus."

The eighth-seeded Venus beat Romanian Sorana Cirstea 6-3 6-4 in the preceding match.

Monday's match will be the 29th between the pair, who last played in the 2017 Australian Open final, with Serena leading the head-to-head record 17-11.

"She looked like she never lost a step," Venus said of her youngster sister.

"She's playing really well and just honing her game.

" When she's missing, it's not by much."

Also moving into the third round was Caroline Wozniaki, the Danish second seed recording a routine 6-4 6-1 win over Lara Arruabarrena.

The fourth-seeded Elina Svitolina cruised to a 6-4 6-3 win over Mona Barthel.

Defending champion Elena Vesnina dropped the first set before she charged back t o life to overpower American Catherine Bellis 2-6 6-1 6-1.

Other second-round winners on Saturday were Carla Suarez Navarro, Aliaksandra Sasnovich, Daria Kasatkina, Julia Goerges, Sofya Zhuk and Danielle Rose Collins.