Serena into semis of WTA Championship

Serena into semis of WTA Championship

Serena Williams of U.S reacts to her win over to Elena Dementieva of Russia during their WTA Tour Championships tennis match in Doha October 29, 2009.

DOHA, Oct. 29 -- World number one Serena Williams of the United States entered the semi-finals of the WTA Championships here on Thursday with a win over Russian Elena Dementieva.

Her 6-2, 6-4 victory confirmed her as the first player through to the last four at the season-ending tournament.

Her sister Venus, who lost to both Dementieva and Serena in her first two matches, beat Russian Svetlana Kuznetsova 6-2, 6-7 and 6-4 but must wait for Friday's results before knowing whether she will continue her action.

Teenager Caroline Wozniacki of Denmark remained undefeated at the 4.5 million dollars championships after beating Russian Vera Zvonareva in a White Group match.

The 19-year-old won 6-0, 6-7 and 6-4 despite suffering agonising cramps in her left thigh.

Serena Williams of U.S hits a return to Elena Dementieva of Russia during their WTA Tour Championships tennis match in Doha October 29, 2009.

Svetlana Kuznetsova of Russia hits a return to Venus Williams of the U.S during their WTA Tour Championships tennis match in Doha October 29, 2009

Vera Zvonareva of Russia hits a return to Caroline Wozniacki of Denmark during their WTA Tour Championships tennis match in Doha October 29, 2009.

Caroline Wozniacki of Denmark reacts during a break in play, with a towel, during their WTA Tour Championships tennis match against Vera Zvonareva of Russia in Doha October 29, 2009.

Elena Dementieva of Russia hits a return to Serena Williams of U.S during their WTA Tour Championships tennis match in Doha October 29, 2009.

Venus Williams of the U.S hits a return to Svetlana Kuznetsova of Russia during their WTA Tour Championships tennis match in Doha October 29, 2009.
(Reuters Photo)