Serena Williams beaten in first round of Brisbane International . Ksenia Pervak of Brisbane wins three -6 6-3 7-6 in marathon match . Australian Sam Stosur also exits to Swede Sofia Arvidsson . Sofia Arvidsson already into first round .
Caroline Wozniacki beaten in first round of Brisbane International . Ksenia Pervak of Kazakhstan wins 2-6 6-3 7-6 in marathon match . Australian Sam Stosur also exits to Swede Sofia Arvidsson . Serena Williams already into second round .