Australian tennis stars Samantha Stosur and Bernard Tomic both secured first-up wins at the Miami hardcourt tournament.
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. Stosur had received a bye in the opening round.
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 to American Sam Querrey 6-1, 5-7, 7-5, having produced a stirring fight-back 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 successful WTA return in her first tournament match since the Australian Open.
Williams beat China's Zhang Shuai 6-2, 6-3 in her first tour match since she was sidelined by a left ankle injury.
The former world number one fired six aces and connected on 64 per cent of her first serves while surrendering only one break to advance to the third round.
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 an 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.
Russian second seed Maria Sharapova also made it through to the third round, beating Israeli Shahar Peer 4-6, 6-3, 6-3.
AAP/AFPTags: sport, tennis, united-states, australia First posted March 23, 2012 11:08:46