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.