World number three Justine Henin-Hardenne of Belgium ensured herself a berth in the semi-finals of the WTA Tour Championships here on Thursday with a 6-4, 6-4 win over Russia's Nadia Petrova.
The diminutive Belgian took exactly 100 minutes to see off her fifth-ranked opponent and ensure her progress with a match against world number one Amelie Mauresmo still to come.
Mauresmo got her challenge back on track by beating Switzerland's Martina Hingis 3-6, 6-1, 6-4.
After losing her opening match to Petrova 6-2, 6-2 the Frenchwoman now needs to beat Henin-Hardenne to qualify for the semi-final.
"It's a great feeling to qualify for the semis," said French Open champion Henin-Hardenne.
"I missed the last two editions of the championships with injury and now I'm coming back from a few weeks off so it's great to be back on top."
If Henin-Hardenne can win her semi then she will end the season as world number one.
But the Belgian insists that grabbing the top spot in the world, which she first occupied in 2003, would not alter her campaign here.
"I enjoy being on the court but I will play the semi-finals with the goal of going to the final, not to be number one," added Henin-Hardenne, who is playing her first tournament since the US Open.
"It will be tough for sure, but I don't even want to look to far. Being back on the court and winning my games is the most important thing for me.
"I missed tennis a lot, and I wasn't sure that I could come. There were lots of doubts, I had a hard time."
Mauresmo, who has occupied the world number one spot for 34 weeks, defeated twice former champion Hingis in an evening battle of day-one losers.
The win left Mauresmo with a chance of reaching the last four - if she can defeat Henin-Hardenne on Friday.
Mauresmo came here having to shrug off a shoulder injury and in her first match was swatted easily by Petrova.
And when Hingis moved ahead it looked as if Mauresmo might throw in the towel.
That not being in the nature of the Australian Open and Wimbledon champ, she roared back to level the tie and then, from 3-1 in the second she motored to seven straight games to finish the resistance of the Swiss miss, winning after 75 minutes on her fourth match point.
"I am still alive," said Muaresmo. "Hingis got my rhythm going and that helped me."
In the Red Group, Kim Clijsters recovered from her opening loss to Maria Sharapova to crush Russia's Svetlana Kuznetsova 6-1, 6-1 to keep her semi-final hopes alive.
The Belgian took just 45 minutes to wrap up victory.
"I was hitting the ball really well early in the match and she made a lot of errors," said Clijsters.
"I got the breaks early and felt more confident."