Belorussian world No.17 Victoria Azarenka beat her second Top 10 player of the week, taking down fourth seed Elena Dementieva 7-6(6) 3-6 6-1. Azarenka raced to a 5-0 lead in the third set, and Dementieva saved three match points to win her first game, but eventually lost after nearly three hours.

Venus Williams was also among the winners on Friday, defeating No.3 seed Dinara Safina 6-4 6-2 in their first career meeting.

The last player to enter the Stuttgart semifinals was Serbia’s Jelena Jankovic, who played her 18th quarterfinal of the year defeating Russian Vera Zvonareva 7-6(8) 7-6(5).

Let’s quickly look at the head-to-head statistics of the semifinalists. Azarenka and Petrova are tied at 1-1 in their career meetings. The last time they played each other was at this year’s Wimbledon and Petrova won in straight sets 7-6(11) 7-6(4). Williams and Jankovic have played each other seven times so far, and the Serb leads 4-3. They last met in the Italian Open quarterfinals, on clay, where Jankovic defended her title. (photos: Getty Images)