Maria Sharapova, breathing down Mauresmo's neck in the rankings, gave the Russian camp even more to shout about as she then scored a routine 6-1, 6-4 win over compatriot Elena Dementieva in her first match.

Then in the late game, Justine Henin-Hardenne of Belgium beat Switzerland's Martina Hingis, playing her first end-of-season championships since 2002, 6-2, 6-7 (5/7), 6-1.

With four former champions and five current or former world number ones on the draw card, Mauresmo was hoping to survive an opening tussle as she returned from a shoulder injury.

Instead, the Australian Open and Wimbledon champion, nursing an injured shoulder which forced her to pull out of her last tournament in Zurich, admitted she never got into gear.

With the race on for the year end number one slot, which is a three-way tussle between Mauresmo, Sharapova and Justine Henin-Hardenne of Belgium, it was not the start Mauresmo wanted as she bowed to Petrova in 1hr 13min.

Petrova raced into a 3-0 lead and didn't look back as she scored her third win in eight meetings with Mauresmo, who will now struggle to keep her wafer-thin advantage in the rankings over Sharapova and Henin-Hardenne.

Sharapova was all business as she dispatched Dementieva in 1hr 27 min.

Dementieva double-faulted to gift Sharapova the opening game and the pattern continued with a total of 16 double faults during the match.