By Beth Harris
The Associated Press

LOS ANGELES - Top-seeded Serena Williams overcame her own uneven play to beat No. 3 Jennifer Capriati 2-6, 6-4, 6-4 in the semifinals Sunday. Older sister Venus was forced out by a leg injury trailing 5-0 in the first set of her semifinal against Kim Clijsters.

Serena Williams will play Clijsters in Monday night's final of the $3 million tournament. Williams won the title a year ago in Germany when Lindsay Davenport couldn't play because of injury.

"Hopefully, I'll be able to play a little better in the final," Williams said.

Venus Williams said she twisted her left ankle in a 7-5, 6-4 victory over Monica Seles on Friday night, but didn't feel the effects until Saturday night. The official diagnosis was a lower leg strain.

"She was really injured," Serena said. "I don't think she should have went out there at all."

Serena Williams needed just over two hours to put away Capriati for her 18th consecutive victory. She is 56-4 this year, with her last loss to Chanda Rubin in August in nearby Manhattan Beach.

Serena Williams had nearly four times the number of winners (42 to 11), but she committed a whopping 53 unforced errors and won just four more total points than Capriati.

"Sometimes she's erratic. That makes it difficult to play her because she can get on a roll and then miss a bunch of shots," Capriati said.

After splitting sets, Capriati took a 3-1 lead in the third before the largest and loudest crowd of the week at Staples Center, where the tournament has been plagued by poor attendance in its first year in Los Angeles. Sunday's crowd was announced as 8,164 in the 20,000-seat arena.

Capriati was within a point of going up 4-1, but she returned Williams' serve long, Williams hit a 115-mph ace and then Capriati missed a forehand as Williams won the first of three consecutive games for a 4-3 lead.

"I had so many chances," Capriati said.

Capriati survived four deuces and two frustrating net cords to hold at 4-4. When the second net cord dropped in, Capriati rushed forward and hit a forehand winner. She headed back toward the baseline, turned around and smacked the saggy net with her racket.

"It's pretty unusual for so many net cords to go one way in a match," she said.

Williams rolled through the final two games, allowing Capriati just three points. Williams used two big serves to hold at 5-4. Capriati led 30-15 on her serve before making three straight errors to lose the match.

"Our intensity levels were so high," Williams said. "She returned very well and hit some amazing shots."

Williams has beaten Capriati six straight times after losing four of their first five career meetings. Their last three meetings have gone three sets.

Capriati finished the year with a 48-15 record and one title, the Australian Open in January.

Clijsters, the fifth seed from Belgium, led 5-0 when Williams called for a trainer. After a brief discussion, Williams approached the umpire to say she was done.

Wearing a white wrap on her left calf and heavy tape on her left ankle, Williams walked over to Clijsters, hugged her and then waved to the fans as she left the court to applause. Williams earned $191,000 for her 13 minutes on court.

"I wasn't really able to move or get on my toes or change direction," Williams said. "I was taped to the max. Things were already going pretty bad. I was trying to end the points quickly."

Williams' quick exit brought back memories of her controversial departure from the Tennis Masters Series at Indian Wells, Calif., in 2001. She pulled out of her semifinal against younger sister Serena at the last minute with tendinitis in her right knee, triggering massive booing by the crowd.

Serena was booed heavily when she beat Clijsters for the title, causing the sisters' father, Richard Williams, to level racial accusations. Serena has said she will not play at Indian Wells again.

"I'll never forget that," Venus said. "It was a pretty intense moment to go through."

A year ago at the WTA Championships in Germany, Clijsters lost a three-set semifinal to Davenport, who injured herself and couldn't play the final against Serena.

"Maybe it's because of me," Clijsters said, grinning.

It was the fourth time in five years that Venus has pulled out from the season-ending championships that determine the WTA Tour's final rankings.

Three of her previous withdrawals came before she even played a match. Last year, she injured her left wrist practicing at home in Florida. In 2000, she had anemia, and in 1998 she had left knee tendinitis. In 1999, she reached the semifinals before losing to Martina Hingis.

Clijsters' groundstrokes painted the lines and she won a game with a 111-mph ace as Williams barely moved off the service line. Clijsters broke Williams in the second game, then served a 40-love game for a 5-0 lead before the match ended.

Williams won just six points and had seven errors in her brief time on court. Clijsters hit 21 winners.

"I just wanted to try to see what I could do," Williams said. "I was a lot more disappointed than what I thought I'd be."