Henin beat the fourth-ranked Ana Ivanovic 6-4, 6-4, and Sharapova defeated No. 7 Anna Chakvetadze 6-2, 6-2 Saturday in the semifinals of the round-robin tournament that features the top eight players.

Ivanovic put up a tougher fight than their last encounter — a 6-1, 6-2 defeat in the French Open final. Henin improved to 3-0 against her.

Henin can equal Steffi Graf's 25-match unbeaten run in 1989 by winning her 10th title of the season. That would make her the first player to win 10 or more titles in a season since Martina Hingis in 1997.

Sharapova won her fourth straight match of the tournament after an injured shoulder had limited her to a single victory since Aug. 31.

"I just thought to myself that four weeks ago you were really doubting yourself, so to be here is really great and to be in the final is even better," said Sharapova, who can move into the top five with a win on Sunday.

The top-ranked Belgian needed long rallies to break Ivanovic six times. Henin held serve nine times despite nine double-faults.

Henin and Sharapova last met in last year's semifinals of the WTA's season-ending tournament. Henin won 6-2, 7-5 (5) to clinch the year-end No. 1 ranking.

Sharapova has beaten Henin only twice in eight meetings, the last at the 2006 U.S. Open final.

The sixth-ranked Sharapova, who won the 2004 season-ending tournament on her debut, broke Chakvetadze twice in each set to improve to 6-0 against her.

"The most import thing is that I've been able to serve without thinking about hurting my shoulder," Sharapova said. "I'm serving and playing freely and that is really important."

Chakvetadze, who has won a career-best four titles this year, failed to convert a break chance in the second game as Sharapova slowly found her game.

"I definitely felt a little bit off to start, especially with my rhythm in the first two games. But I came through a couple of break points and that gave me confidence," Sharapova said.

Sharapova, who dropped out of the top five for the first time in three years after winning a career-low one singles title in 2007, got a break in the third game when her opponent double-faulted.

She broke again in the fifth before serving out the set after Chakvetadze's forehand went into the net following a long rally.

"It was tough today because there were so many easy mistakes from me," Chakvetadze said.