WTA Finals: Caroline Wozniacki earns win over Maria Sharapova

Caroline Wozniacki also beat Maria Sharapova at the US Open earlier this year

Caroline Wozniacki beat Maria Sharapova 7-6 (7-4) 6-7 (5-7) 6-2 in a marathon match at the WTA Finals in Singapore.

Both players were broken twice in a gripping first set, which went to a tie-break, won by Wozniacki.

The Dane served for the match at 5-4 up in the second - but was broken and lost the set on another tie-break.

In the decider, Wozniacki was the dominant force as she won four games in a row from 2-2 to earn victory in three hours and 14 minutes.

"I'm feeling a little tired," said Wozniacki. "In the third set, I stepped it up and started hitting through the ball a bit more."

In the following match, on court after 23:00 local time, Wimbledon champion Petra Kvitova lost 6-2 6-3 to Agnieszka Radwanska.

Wozniacki had beaten her Russian rival at the US Open earlier this year and their latest contest provided plenty of drama and twists.

Sharapova came back from 3-0 down in the first set to level and broke her rival in the ninth game to take a 5-4 lead.

But, serving for the first set, Sharapova opened up with the first of two double faults in the game as Wozniacki levelled and held her own serve to go 6-5 in front.

Two more double faults from the Russian in her next game gave Wozniacki a set point - only for Sharapova to find the line with a powerful forehand before the set went to a tie-break.

Wozniacki trailed 4-2 but recovered to lead 6-4 and took the set when Sharapova served her ninth double fault.

A problem with the lights in the second set caused problems for Wozniacki but she manoeuvred her way to a 5-4 lead only to be broken when serving for the match.

Another tie-break was needed and this time Sharapova came out on top to level.

In the deciding set, eighth seed Wozniacki's perseverance and pressure finally helped her pull clear for a hard-earned a hard-fought win over the world number two.