Agnieszka Radwanska of Poland holds aloft the Billie Jean King Trophy after defeating Petra Kvitova of Czech Republic in the title match of the WTA Finals.
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Kvitova of Czech Republic reacts to a point against Maria Sharapova in the way to a surprise victory over the Russian in the WTA Finals.
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Sharapova of Russia looks dejected after slipping to a shock defeat to Kvitova in the semifinals.
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Radwanska ended the hopes of Spain's Garbine Muguruza in the semifinals at the WTA Finals.
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Day Six —
Muguruza beat Kvitova 6-4 4-6 7-5 at the WTA Finals in Singapore to win the White Group and progress to the semifinals.
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Day Six —
But it wasn't all bad news for Kvitova, the two-time Wimbledon champion ...
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Day Six —
She joined Muguruza in the last four when Lucie Safarova, pictured, topped Angelique Kerber in straight sets, 6-4 6-3.
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Day Six —
Kerber's week began well when she downed Kvitova but then the German lost to Muguruza and Safarova.
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Day Six —
In Saturday's semifinals, Sharapova, pictured, played Kvitova and Muguruza faces Radwanska.
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Day Five —
That about sums it up for Simona Halep. She lost to Radwanska on Thursday and was eliminated at the WTA Finals.
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Day Five —
A frustrated Halep, seen here with coach Darren Cahill, fell 7-6 (7-5) 6-1. The Romanian was the highest ranked player in the field at No. 2.
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Day Five —
Sharapova knew she made the semifinals even before she played Flavia Pennetta but still beat the Italian 7-5 6-1, rallying from 4-2 down in the first.
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Day Five —
Sharapova finished at 3-0 in the Red Group and progressed with Radwanska. Pennetta, meanwhile, played the final match of her career.
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Day Four —
Kvitova bounced back from her opening defeat at the WTA Finals in Singapore by beating fellow Czech Lucie Safarova 7-5 7-5 on Wednesday.
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Day Four —
Kvitova has now beaten her friend eight times in a row. Next month they will line up together against Russia in the Fed Cup final, seeking to give the Czech Republic a fourth title in five years.
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Day Four —
Kvitova will play unbeaten Spanish second seed Muguruza in her final White Group match. The 22-year-old has two wins from two after beating Angelique Kerber 6-4 6-4 in Wednesday's second match.
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Day Four —
Sixth seed Kerber, who would have reached the semis with victory over Muguruza, faces Safarova in her closing match.
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Day Three —
Sharapova celebrates after beating top seed Halep 6-4 6-4 in their second Red Group round-robin match in Singapore.
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Day Three —
Halep could have qualified for the semifinals with victory, but the Romanian lost seven out of eight games from 4-4 in the opening set and the Russian held off her late fightback.
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Day Three —
Pennetta signs autographs for fans after defeating Radwanska 7-6 (7-5) 6-4 in Tuesday's earlier Red Group match. Italy's U.S. Open champion kept her semifinal hopes alive ahead of her closing match against Sharapova.
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Day Three —
Radwanska led 5-3 in the opening set, and the Polish fifth seed saved three match points before her second defeat in three days.
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Day Two —
Spain's rising star Muguruza opened her White Group campaign with a 6-3 7-6 (7-4) win against Safarova of the Czech Republic on Monday.
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Safarova beat the 22-year-old in this year's French Open quarterfinals in their only other meeting, but the world No. 9 was sidelined by a debilitating bacterial infection after her first-round defeat at the U.S. Open.
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Day Two —
Kvitova, who has also struggled with health issues this year, lost 6-2 7-6 (7-3) to Germany's Angelique Kerber in their opening White Group match.
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Kerber had lost her previous four clashes with her fellow left-hander, who won the tournament in 2011 when it was held in Istanbul.
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Day One —
Sharapova triumphed against Radwanska on Sunday in her first completed match since the Wimbledon semifinals. The world No. 4 pulled out with an arm injury during her return in Wuhan last month.
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Day One —
Sharapova battled Radwanska for nearly three hours on Sunday before triumphing 4-6 6-3 6-4.
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Day One —
World No. 2 Halep, meanwhile, needed just 70 minutes to thrash Pennetta 6-0 6-3.
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Day One —
Pennetta, who will retire at the end of this season, was unable to regain the form that gave her a straight-sets victory over the 24-year-old in the U.S Open semis.