Russia's Vera Zvonareva has reached the third round of the US Open after a three-sets victory over the Ukraine's Kateryna Bondarenko.
The number two seed began slowly, but managed to take the first set to a tie-break, which she won.
Bondarenko, who was a 2009 quarter-finalist, found herself 3-1 down in the second, but won five straight games to level the contest.
Zvonareva upped her game for the decisive set, despite her opponent making her work for the victory.
The 2010 runner-up will now face Anabel Medina Garrigues in the next round after the number 30 seed defeated Brit Laura Robson in straight sets.
