Elena Dementieva 7-6(9-7), 3-6, 6-3.
In the semifinals, Williams stormed to a first set lead before some errors from Williams assisted Jankovic in taking set two. Williams hit a backhand long on set point.
In the final set, Williams broke serve to reach 2-1 before surviving a six deuce game to hold serve for 4-2.
With Jankovic hitting more and more topsin to keep more balls in play, Williams also varied the pace of her balls by adding more topspin herself.
The difference in the end was Williams' aggression while minimizing her errors. She would strike two backhand winners to break Jankovic's serve and win the final game including a backhand crosscourt winner on matchpoint.
“What got me through the match was just being consistent at the right times,” Williams said. “My game is about being aggressive and taking chances, but what I really needed to do today was put a lot more balls in play and be a little smarter. I played a little more defensively that I usually do, but it was worth it.”
Williams has met Zvonareva six times and leads head to head 5-1. In their last meeting, Williams won at Rome in the spring 7-5, 6-2. Zvonareva finished as finalist this fall at Moscow and Linz. Williams took her second title of the year last month at Zurich.
“I’ve been in a bunch of pressure situations, so it won’t faze me,” Williams said. “I’ll just focus on what I’m doing when I play Vera. That’s all I can do. We’ve played a number of times and I guess I have a little bit of an advantage. Hopefully that will help me in the final.”