Samantha Stosur has blitzed shellshocked Russian Nadia Petrova to storm into the second week of the French Open.

Stosur made light of the heavy conditions and a losing record against Petrova with a 6-3 6-3 rout at Roland Garros on Friday.

Victory vaulted Australia’s 2010 runner-up into a fourth-round match-up on Sunday with American teenager Sloane Stephens, the surprise packet of the tournament.

Stosur trailed Petrova 5-2 in head-to-heads and lost her most recent encounter with the world No.29 at Indian Wells in March.

The sixth seed also likes it hot, but it was a cool and overcast day in Paris.

Never mind the details, though, the US Open champion still managed to produce her best performance of the championships to stride to within a win of a likely quarter-final blockbuster with world No.1 Victoria Azarenka.

Stosur showcased her full array of shots on court one – mixing signature forehand rockets with delicate drop shots and one exquisite backhand down the line – to notch her 16th win from 20 claycourt outings in 2012.

Stosur raced to a 4-0 lead before Petrova could even blink.

After opening the match with a ferocious forehand cross, the onslaught continued as Stosur broke Petrova’s first service game with a series of booming winners.

Petrova was simply unable to cope with Stosur’s brute early on and the Australian grabbed the vital double break with a massive off-forehand return.

A brief lapse handed the Russian one break back, but Stosur steadied to coolly serve out the first set.

A seemingly demoralised Petrova gifted Stosur the first of two service breaks in the second set with a double-fault in the third game to fall behind 2-1.

Stosur said thanks very much and finished Petrova off with a cold-blooded backhand winner after one hour and eight minutes.

The Australian title contender is yet to drop a set in the tournament.

Her next opponent, 19-year-old Stephens, had never won a match in Paris before this campaign, but has powered into the last 16 also without dropping a set.