Stanford (California):Serena Williams injured her left knee and retired from her semifinal of the Bank of the West Classic, advancing Canadian qualifier Aleksandra Wozniak to the final.
Wozniak will meet sixth-seeded Marion Bartoli in the final, with the Frenchwoman beating Japan veteran Ai Sugiyama 6-3, 6-3.
Williams was down 6-2, 3-1 against Wozniak when she withdrew yesterday, joining sister Venus and Lindsay Davenport on the list of injured home players ahead of the US Open and next month's Olympics.
"It was hurting in practice and I didn't really practice too long because it was hurting," Williams said.
"After I got off, it was really swollen. I thought that I have to play really fast."
Williams lasted only 46 minutes before pulling out of the match. She said the injury is different than one that forced her to undergo surgery on her left knee in 2003 and miss eight months. But that knee has bothered her since, forcing her to drop out of the 2004 Athens Olympics and to miss significant time again in 2006.
But Williams had felt healthy most of this year, playing a busy schedule since winning in Miami in the beginning of April. She played 26 matches in a three-month span that went through her loss in the Wimbledon final to Venus.
Then she returned home and played for the Washington Kastles of the World Team Tennis league before arriving at Stanford for her debut in this tournament. Williams wouldn't blame her decision to play team tennis on her latest setback.
It's been quite a week for Wozniak, who needed to win three matches in the qualifying tournament just to make it into the main draw. She then beat eighth-seeded Francesca Schiavone in three sets in the first round, before knocking off Sybille Bammer and Samantha Stosur to make it to the semifinals.
Wozniak is the first qualifier to make the final at this tournament since the inception of computer rankings in 1982.
This is just the second career final for Wozniak, who made it to a lower-tiered championship match in Morocco last year. Wozniak, who entered the week ranked 85th in the world, should be close to reaching her goal of being a top 50 player by next week.
"I'm really happy with the way I played this week, coming out of the qualifying is not easy," Wozniak said. "It's a lot of matches in one week."
Bartoli has had a sporadic year after making it to the Wimbledon final a year ago. She lost in the first round at the Australian Open and French Open and had not made it to a final since losing to Venus Williams last year at Wimbledon.
Bartoli broke Sugiyama at love to take a 4-2 lead in the first set and then won a four-deuce game on Sugiyama's serve to go up 2-1 in the second. Bartoli finished it off by breaking Sugiyama for the fourth time of the day, winning for the first time in six career meetings against Sugiyama. However, this was the first time the two had met since 2006.
"I was just not on the same level. It's as simple as that," Bartoli said. "Everything in my game has improved."