Belgium's Kim Clijsters will become world number one next week for the first time since 2006 after she reached the Paris Open semi-finals by beating Jelena Dokic 6-3, 6-0 on Friday.

The Australian Open champion has gained enough ranking points to go above Denmark's Caroline Wozniacki, who is not in action this week and has been constantly criticised in the media for holding the top spot despite never having won a Grand Slam.

"I'll try in French...I'm very happy to be number one again," Clijsters told the crowd as she was handed a giant number 1 made out of flowers from tournament director and retired former French number one Amelie Mauresmo.

"Thanks for all your support and I hope I can also win the tournament maybe. It's a nice feeling but it doesn't change anything for me personally."

Clijsters has been world number one three times before, twice in 2003 and once in 2006. She retired to have a child in 2007 and then made a stunning return to tennis.

Victory in the 2009 US Open came only weeks after her comeback and she has since added last year's Flushing Meadows title and last month's Australian crown to her list of Grand Slams.

The 27-year-old had a shaky start at the Paris Open, taking place a short walk from the home of the more famous French Open, when she lost the first four games of her opening match against Kristina Barrois on Wednesday before roaring back.

Australian qualifier Dokic, a former world number four, has been enjoying a resurgence in fortunes so far this year after years in the wilderness and she went 3-0 up in the first set as Clijsters again failed to find top gear early.

The wobble did not last long as her serve kicked in and she showed her class at the net with Dokic beginning to falter.

Clijsters, wearing lime green in front of another half-full crowd at the Stade Coubertin, wrapped up the first set when Dokic fired into the net.

Dokic was hitting the ball harder in the second set but the Belgian top seed had more control, striking some superb winners down the line and easing to victory with her opponent's game falling to pieces.

Clijsters, whose chances of winning the tournament for a second time have increased after the withdrawal of Maria Sharapova because of illness, will next meet the winner of the last quarter-final between Kaia Kanepi and Dominika Cibulkova.

American world number 48 Bethanie Mattek-Sands again proved that she is not only a doubles player with a 7-6, 2-6, 6-3 victory over sixth seed Andrea Petkovic of Germany.

The 25-year-old Mattek-Sands again turned up in a remarkable outfit including a black-and-white hooped top and knee-length socks.

Czech fourth seed Petra Kvitova will play her in the last four on Saturday after overcoming seventh seed Yanina Wickmayer 5-7, 6-3, 7-6 with their frosty handshake at the net after a tense last set the main talking point.