Samantha Stosur, Bernard Tomic win in Miami.
AUSTRALIAN No1s Samantha Stosur and Bernard Tomic and returning queen Serena Williams all scored first-up wins at the joint WTA and ATP tournament in Miami.
EAfter enjoying a bye in the opening round, sixth-seeded Stosur cruised into the third round of the women’s event with a 6-4 6-0 victory over Russian qualifier Valeria Savinykh.
The US Open champion next faces South African Chanelle Scheepers.
Tomic booked a meeting with Spanish fifth seed David Ferrer after downing Ukraine’s Sergiy Stakhovsky 7-6 (7-4) 6-3 in the men’s first round.
But fellow Australian Matt Ebden lost a seesawing night match to American Sam Querrey 6-1 5-7 7-5 after producing a stirring fightback after losing the first set in just 24 minutes.
While it was a low-key day for the men, a host of women’s stars were in action, including Serena Williams, who made a triumphant WTA return in her first tournament match since the Australian Open.
Williams beat China’s Zhang Shuai 6-2 6-3 after being sidelined by a left ankle injury.
The former world No.1 fired six aces and connected on 64 per cent of her first serves while surrendering only one break to advance into the third round with an 80-minute victory.
“I was a little bit rusty and a little bit nervous too,” Williams said.
“I haven’t played here for so long and I wanted to do well. So I was really nervous out there, but I think now I’ve gotten one under I’ll be better.
“I’m always a little nervous in the first round. I kind of chill out after that,” Williams said. “Last time I played I played horrible and I was thinking as long as I don’t hit a ball into the stands I’ll be good.
“I didn’t do that today, so it worked out well for me.”
The 13-time grand slam singles champion will next face Italy’s Roberta Vinci, who ousted Bulgarian Tsvetana Pironkova 7-5 6-1.
Williams played for the US Fed Cup team last month, winning two singles matches in a 5-0 World Group II victory over Belarus.
But she had not been in a tour match since losing to Russia’s Ekaterina Makarova in the round of 16 at Melbourne.
Five-time Miami winner Williams, the 10th seed on the women’s side of the $US9.6 million ($A9.27 million) event, withdrew before her Brisbane quarter-final match because of the ankle injury in her only other WTA start this year.
Kim Clijsters also continued her comeback from injury, ousting German 14th seed Julia Goerges 6-2 7-5 to reach the third round.
And second-seeded Russian Maria Sharapova beat Israeli Shahar Peer 4-6 6-3 6-3 in her second-round match.