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Kim Clijsters shook off six weeks on the sideline, a car accident and top-ranked Caroline Wozniacki to win the season-ending WTA Championships on Sunday.

Clijsters used the same focus and concentration a day after escaping unscathed from a fender-bender to defeat Wozniacki 6-3, 5-7, 6-3 for her third WTA Championships title.

The 27-year-old Belgian, sidelined due to an infected foot, played in her first tournament since winning the U.S. Open in September and improved to 6-0 in finals since coming out of retirement midway through 2009. On Saturday, she defeated Samantha Stosur in the semifinals just hours after a truck hit the right front door of her courtesy car.

The fourth-ranked Clijsters appeared to be on her way to an easy win when she took a 4-1 lead in the second set, but she allowed Wozniacki back into the match before regaining control in the deciding third set with powerful groundstrokes and strong retrieving skills for her fifth title of the year.

"It was a tough match," Clijsters said after earning $1.4 million with the win. "I'm glad I won and it must be disappointing for Caroline, but I don't know how many more years I'm going to keep doing this."

Clijsters won her 40th career title after victories in Brisbane, Miami, Cincinnati and at the U.S. Open this year. She became the fifth player in WTA history to win the season-ending tournament three or more times, joining Martina Navratilova (8), Steffi Graf (5), Chris Evert (4) and Monica Seles (3).

The 20-year-old Wozniacki took over the No. 1 ranking from the injured Serena Williams last month, but was unable to back it up with a win in Doha and is still without a Grand Slam title.

Wozniacki has won the most tournaments this year — six — but has yet to win a major tournament. She's still looking for wins against Clijsters, Justine Henin, Venus and Serena Williams.

"I've had a fantastic year," Wozniacki said. "I won six tournaments. I've beaten so many good players. You know, you cannot win every match. I've made the finals of the championships, and I lost one match today.

"I will come back in the offseason and train, but right now I'm proud of my season."

Clijsters said the Dane has shown great promise.

"She will win a Grand Slam. She is too good of a player not to," Clijsters said. "She's young. She's No. 1. ... She just has to keep working the way that she has been working. She's been doing really good things, and the good things will keep coming."

Clijsters took a 2-0 lead en route to winning the first set, using powerful forehands and well-timed backhands. She closed out the set by breaking Wozniacki for the third time.

Clijsters, who won the season-ending title in 2002 and 2003, went up 4-1 in the second, taking advantage of Wozniacki's weak second serve and lack of forehand winners. But Wozniacki rallied to tie the match at 5-5 and broke to go up 6-5 on her way to winning the set after Clijsters hit long.

"I just went behind the baseline a little bit too far," Clijsters said. "I let her dominate the rallies, and that was something I was doing well leading up to that point.

"I felt after a couple rallies, yeah, felt my legs just a little bit tired. Then you automatically become a little bit too defensive. I think that's something that I realized, luckily, in time."

Wozniacki came out strong in the third set, forcing Clijsters to make four unforced errors in the first game. But Clijsters didn't panic, settling down for a 2-1 lead. That prompted Wozniacki's coach and father, Piotr, to give his daughter a courtside pep talk while she rested a bag of ice on her head in the sweltering heat.

Clijsters kept the pressure on, moving Wozniacki around the court and hitting several powerful forehands to go up 5-2. Wozniacki won a game before Clijsters clinched it when Wozniacki hit a return into the net.

"In the third set, you know, it was very close," Wozniacki said. "She played really well, especially in the important moments. Definitely, the experience, you know, mattered a little bit today."

In their only other meeting, Clijsters defeated Wozniacki for the 2009 U.S. Open title. Clijsters won at Flushing Meadows that year in only her third tournament back from a 2½-year retirement after getting married and having a daughter, Jada.

In Doha, Clijsters beat an ailing No. 8 Jelena Jankovic in her opening match, followed by a win over No. 10 Victoria Azarenka. She lost to No. 2 Vera Zvonareva on Friday before rallying with wins over Stosur and Wozniacki.