Li Na to play Petra Kvitova in semifinals of WTA Championships on Saturday . Czech star will become Asia 's highest-ranked player if she beats the Serbian . Petra Kvitova will face world No . 1 No . four Serena Williams in other last- four clash . Chinese goes through despite losing to already-eliminated Sara Errani .
Li Na to play Petra Kvitova in semifinals of WTA Championships on Saturday . Czech star will become Asia 's highest-ranked player if she beats the Serbian . Petra Kvitova will face world No . four Serena Williams in other last- four clash . Chinese goes through despite losing to already-eliminated Sara Errani .