Bernard Tomic and Serena Williams cruise at Argentina Open in U.S. . World No . 7 Federer beats Argentina 's Serena Williams in straight sets . Serena Williams defeats Kazakhstan 's Alexandra Dulgheru 6 -0 . Elsewhere , the seventh seed , Petra Kvitova from the Czech Republic , beat Serbia 's Bojana Jovanovski 6-4 6-2 and ninth seed Jelena Jankovic , from Serbia , beat Russia 's Alisa Kleybanova 6-3 6-2 . British qualifier Dan Evans springs surprise by beating Bernard Tomic .
Bernard Tomic and Serena Williams cruise at Argentina Open in U.S. . World No . 7 Federer beats Argentina 's Serena Williams in straight sets . Serena Williams defeats Kazakhstan 's Alexandra Dulgheru 6 -0 . British qualifier Dan Evans springs surprise by beating Bernard Tomic .