Dementieva, seeded fifth, piled up five service breaks in a 6-2, 7-5 victory over Francesca Schiavone. She won as many points -- 36 -- as the Schiavone did when Schiavone served.
Other matches Sunday saw third-seeded Svetlana Kuznetsova survive a 6-2, 6-7 (3-7), 7-5 bout with Alisa Kleybanova in an all-Russian pairing that took 2 hours, 23 minutes and Slovakia's Daniela Hantuchova stop Frenchwoman Virginie Razzano 6-3, 6-0 in 65 minutes.
The high-profile tournament features the world's top two ranked women players.
No. 1 Serena Williams and second-ranked Dinara Safina were given first-round byes. The only Top 10 player missing from the field is No. 6 Venus Williams.
The $600,000 Medibank International is a final prep tournament before next week's Australian Open, the first major of 2010. The tournament champion, to be determined Friday, will collect $98,500.
Copyright 2010 by United Press International.