Maria Sharapova swept past Sam Stosur 6-0 6-3 at the WTA Championships on Friday to retain a small chance of finishing the year as the No.1-ranked player in the world.

If Victoria Azarenka beats Li Na in the last round-robin match of the day, however, she will be assured of staying No.1.

Sharapova has already joined Serena Williams in qualifying for the semi-finals of the elite, eight-women event – both going through with perfect three-from-three records in the round-robin phase.

The Russian rolled through the first set, allowing Stosur only five points. The Australian was an alternate who replaced defending champion Petra Kvitova, who withdrew because of illness.

Stosur put up more of a fight in the second set, but Sharapova ended it with a smash.

The Russian won the French Open this year and briefly held the No.1 ranking.