kumero,That last i saw ashley doubles match on CCTV5(A sports channel in China).
Tiantian/Sun played terrible from the first set,but they won some key points,so they took the first set.
I have to say Ashely and her partner played awesome tennis! Ashely has good volley and her partner has good serve.
So I think the two factors made them took advantage in the match.
However,Li/Sun had too many UEs on baseline.
I hope u'll be satisfy with my answer.