Sun Tiantian ousted defending champion Serena Williams in the second round matchup on Wednesday of the China Open WTA tournament, beating the fourth seed 6-2, 7-6(7).

    BEIJING, Sept. 21 (Xinhuanet) -- Women's doubles Olymlpic gold medalist Sun Tiantian ousted defending champion Serena Williams in the second round matchup here on Wednesday of the China Open WTA tournament, beating the fourth seed 6-2, 7-6(7).

    Breaking her former world number one opponent at the very first game of the match, the doubles specialist Sun took the first set 6-2 as Serena played nine unforced errors as well as two double-faults against Sun's three errors and 78% of first serve percentage.

    Again in the second set, the fourth-seeded Serena failed to pull herself out of the sluggish form and doublt-faulted to let Sun overtake the lead 5-4 before breaking the Chinese for the third time in the set to force tiebreaker.

    Against the apparently slowing down Serena, Sun wrapped up the match after the American saved four match points from trailing 6-3 in tiebreaker, but the 24-year-old Sun held back with tireless rallies and forehanded a winner to take it 9-7. Enditem