Cincinnati, OH, USA, 12 August 2014 | tennis.com.au

Sam Stosur has rallied impressively to oust Varvara Lepchenko in her opening match at the WTA Cincinnati event.

Facing a 3-5 deficit in the second set, Stosur reeled off four consecutive games to post a 6-2 7-5 victory over the left-handed American.

The win sets up another meeting with world No.1 Serena Williams; just last week in Montreal, Stosur faced Williams in the second round and fell in straight sets.

The world No.22 won her third straight match over Lepchenko, overcoming six double faults to win 74 per cent of her first serves and break serve on six occasions.

Fellow Australian Casey Dellacqua fell to Pauline Parmentier earlier on Monday at the Premier-level hardcourt event.

Dellacqua, the world’s newest addition to the top 30, lost 7-6(4) 6-2 to the French qualifier, who earlier this season reached the fourth round at Roland Garros.

It marked the very first time in 2014 that Dellacqua has lost in the first round of a WTA event, a sign of impressive consistency.

Less than 12 months ago, Dellacqua was ranked outside the world’s top 200.