World number one Caroline Wozniacki [ Images ] reeled off 12 successive games to ease into the semi-finals of the Qatar Open after a 6-2, 6-0 demolition of Italian Flavia Pennetta [ Images ] on Thursday.

Second seed and world number three Vera Zvonereva was made to work harder for her semi-final spot after a 7-5, 6-7, 7-5 win over Slovakia's Daniela Hantuchova [ Images ] in a match that lasted more than three hours.

Having lost the opening two games, Dane Wozniacki did not drop another in a ruthless display to remain on course for a second straight title after winning the Dubai [ Images ] championships on Sunday.

Wozniacki next faces Marion Bartoli [ Images ] after the Frenchwoman swatted aside China's Peng Shuai [ Images ] 6-2, 6-2.

"I thought I played well. It could have been 6-1 in the second set instead of 6-2, even 6-0. But it was a great performance overall," said Bartoli.

Russian Zvonereva will play Jelena Jankovic [ Images ] for a place in the final after the Serb downed Czech Klara Zakopalova 6-2, 6-4 despite being troubled with a knee injury during the second set.