Sam Stosur did some pre-match routines to prepare for a very important match with Li Na.
Li Na waited in the wings for her match with Sam Stosur. The winner would reach the semifinals.
Sam Stosur went into the match with an edge, having won all five of their previous meetings.
The crowds continued to break the 10,000 mark at the Sinan Erdem Dome on the fourth day of play.
Sam Stosur served up a 61 60 win over Li Na, Li's worst loss in almost five and a half years.
Agnieszka Radwanska walked on court, needing to win a set on Petra Kvitova to reach the semis.
Things looked rough for Petra Kvitova as she fell behind 5-1 in the first set to Aga Radwanska.
Petra Kvitova staged a sudden comeback to win the first set and record a 76(4) 63 victory.
By virtue of the straight set loss, Agnieszka Radwanska did not qualify for the semifinals.
Victoria Azarenka had already won her group but psyched herself up to play Marion Bartoli.
Marion Bartoli's only win in eight previous meetings with Victoria Azarenka was by retirement.
Victoria Azarenka started slowly, then built a 75 20 lead, but then was again in trouble.
Marion Bartoli, who was the first alternate, never gave up to beat Victoria Azarenka, 57 64 64.
Sam Stosur toured the TEB BNP Paribas WTA Championships, including the BNP Paribas suite.
WTA legends Iva Majoli and Mary Pierce stopped by Istanbul and received star Oriflame treatment.