Former top-ranked Caroline Wozniacki advanced to the quarter-finals of the Kremlin Cup on Wednesday by beating Urszula Radwanska of Poland 6-1, 6-3, while second seed Marion Bartoli was knocked out.
Sofia Arvidsson of Sweden posted the biggest surprise of the tournament so far by eliminating Bartoli 6-3, 6-0 in the second round.
The third-seeded Wozniacki won five consecutive games in the first set and then broke Radwanska twice in the second to take a 5-2 lead. She then wasted four match points when trying to serve out the match before Radwanska broke to stay in the contest. However, the Pole sent a forehand wide in the next game to hand Wozniacki the victory.
She next faces defending champion Dominika Cibulkova of Slovakia, who advanced to the final eight with a 6-2, 6-3 win over Tsvetana Pironkova of Bulgaria.
Arvidsson, who won her second career title in Memphis this year, will face either seventh-seeded Russian Maria Kirilenko or Yaroslava Shvedova of Kazakhstan.
The result means the 10th-ranked Bartoli cannot overtake No. 9 Samantha Stosur and will remain the second alternate at the season-ending WTA Championships next week in Istanbul.
Klara Zakopalova advanced to the final eight by defeating eighth-seeded Lucie Safarova 6-4, 6-4 in an all-Czech match, while Valeria Solovieva of Russia moved into the second round by downing Elina Svitolina of Ukraine 6-4, 6-2.
In first-round action, Kirilenko topped fellow Russian Elena Vesnina 7-5, 6-1.
In men’s second-round play, Malek Jaziri of Tunisia upset the third-seeded 2010 champion Viktor Troicki of Serbia 6-1, 3-6, 6-2.