Top-ranked Jelena Jankovic of Serbia and Michelle Larcher de Brito of Portugal beat Team Americas 6-4, 7-5.
Williams will play Jankovic in singles on Thursday.
Zvonareva's match featured 13 breaks of service, and the Olympic bronze medalist trailed in both sets. She came back from 3-5 down in the first set, and recovered from a 2-0 deficit in the second.
Mirza returned to play after a right wrist injury cut short her season in 2008.