Montreal, QC, Canada, 7 August 2014 | tennis.com.au

Serena Williams has romped to victory against Sam Stosur on Wednesday in the second round of the WTA Rogers Cup in Montreal, Canada.

Later in the day, Stosur’s compatriot Casey Dellacqua fell in the last 32 to No.2 seed Petra Kvitova.

It was a tough draw for Australia’s top two ranked women, with Williams currently world No.1 and on a winning streak following her title run last week in Stanford, and Kvitova the reigning Wimbledon champion.

Dellacqua went toe-to-toe with Kvitova in the opening stages of the match, and even scored two break points when she went up 15-40 in the fifth game.

But following a rain delay, Kvitova returned to court and swept the next three games to build a 5-2 lead.

After taking the opening set, she broke immediately in the second to establish the ascendency, and ran out a 6-3 6-2 winner in one hour and 12 minutes.

In the match precending that battle on Court Centrale, Williams posted a 6-0 6-2 victory over Stosur in less than an hour to advance to the third round.

There, the world No.1 and top seed will take on 15th seed Lucie Safarova of the Czech Republic.

In a rematch of their 2011 Rogers Cup and US Open finals, Williams was in imperious form, slamming 10 aces and winning 20 of 22 points on her first serve. She also produced 23 winners to just 12 errors.

Since falling to Stosur in that US Open final, Williams has not dropped a set against the Australian in three subsequent victories.

Stosur next heads to Cincinnati for the Premier-level Western & Southern Open, a combined ATP-WTA event.