Defending champion Li Na has come from a set down to beat Christina McHale 3-6 6-2 6-1.
Li failed to find her form early on in the first set and was under threat after being broken early on by McHale.
Despite finding a break of serve of her own, Li continued to make errors throughout the opening games and gifted a second break to McHale who managed to hold on to take the first set.
A much improved Na appeared in the second set and her serve started to cause problems for her American opponent.
The seventh seed broke McHale to take a crucial lead in the second set but was forced into holding a couple of tough service games before finally taking the second set 6-2.
Li finally seemed to be finding some of her best tennis in the third set and started to apply pressure on a tiring McHale.
McHale failed to serve as well as the previous two sets and Li wrapped up the match with a 6-1 victory in the third.