Serena Williams wins at Doha tennis event

Williams rose to 3-0 overall at the round-robin tournament, fueled by a six-game winning streak after the fifth-seeded Dementieva, a Russian Olympic gold medalist, took a 2-1 lead in the first set.

"It was definitely a match I had to be really focused for because she's a really good player," Williams said. "She's one of those late bloomers who tends to get better and better and better as every year goes on (and) I was probably playing the most fit girl on tour."

Third-seeded Svetlana Kuznetsova of Russia, this season's women's French Open winner, lost 6-2 6-7 (3-7) 6-4 to Serena's older sister, Venus, the seventh-seed and defending champion.

Venus rose to 1-2, while Kuznetsova sank to 0-2.

Copyright 2009 by United Press International.