Serena Williams reels off another rapid fire victory over rival Maria Sharapova

Serena Williams returns a shot to Maria Sharapova during their final tennis match of the WTA Championships in Istanbul (AP)

Serena Williams continued her good run of form against Maria Sharapova, beating the Russian in straight sets to win the final of the WTA Championships in Istanbul.

Williams has now won 10 of the 12 meetings between the pair and has now avenged her 2004 defeat to Sharapova in the final of the same tournament with a 6-4, 6-3 win yesterday.

The 31-year-old American, who also lost the Wimbledon final to Sharapova that year, never looked in trouble as she won inside an hour and a half in Turkey. The success brought Williams her third WTA Championship title and her seventh title of a highly successful 2012.

There was better news for Russia in the double's tournament as the qualifiers Maria Kirilenko and Nadia Petrova completed a weekend of upsets to beat the second seeds Andrea Hlavackova and Lucie Hradecka.

The world No 5, David Ferrer, beat the unseeded Ukrainian Alexandr Dolgopolov 6-1, 3-6, 6-4 to win the Valencia Open for the third time yesterday, claiming his sixth ATP World Tour title this year.

The local favourite, who was pushed all the way in a gruelling third set, climbed into the stands after winning to embrace his friend and the former world No 1 Juan Carlos Ferrero, who retired from the sport earlier in the tournament.

"I am delighted to win here at home in front of my fans and my family," Ferrer told Spanish television in the Agora building in Valencia's City of Arts and Sciences complex.

"It was extra special today because Juan Carlos Ferrero has retired here and I wanted to dedicate the title to him."

The match was evenly-balanced in the final set with the world No 21 Dolgopolov, who defeated the defending champion Marcel Granollers in the quarters, making life difficult for Ferrer with his big serves and clever changes in lines of attack.

The pressure seemed to get to the 23-year-old, however, and he netted a straightforward shot on match point.

"It was a very tough game," Ferrer said. "He made it very hard for me throughout and he pushed me to the very limit. It was about keeping my concentration and I managed to do that."