Doha: Top seeded Caroline Wozniacki stayed on course for her second straight title in the Gulf with a commanding 6-2, 6-0 win over Italian Flavia Pennetta in the quarter-finals of the WTA Qatar Open on Thursday.

Second seed Vera Zvonareva also advanced but not before she was taken the distance by marathon girl Daniela Hantuchova, who played her third consecutive three-setter of the tournament. Zvonareva won 7-5, 6-7 (5/7), 7-5.

The 20-year-old Danish superstar Wozniacki was clinical in her victory over the 15th-ranked Pennetta to set up a semi-final clash with Frenchwoman Marion Bartoli, who earlier in the day thrashed China's Peng Shuai 6-2, 6-2.

The second semi-final will be played between Zvonareva and fifth seeded Jelena Jankovic, who overcame a knee injury to beat Czech Klara Zakopalova 6-2, 6-4.

Pennetta, who was playing in Qatar for the first time, began sensationally by breaking Wozniacki in the very first game of the match, but that proved the only bright spot for her as the Dane raised her level of play and breezed to victory.

Wozniacki now holds a 100 percent win record over Pennetta, triumphing in all their seven matches beginning at Bastad in 2009.

"I am very happy to make the semi-finals," said Wozniacki, who won the Dubai Open last week, adding that the fourth game when she broke back was the turning point of the match.

"I had to go for my shots in the game. That was the key," added Wozniacki, who promptly put on a Liverpool jersey after the match to show her support for the club.

"I am a big Liverpool fan. I got this shirt today from the Qatar Tennis Federation. Liverpool are playing today (in the Europa League) so I thought I should wear it and show my support," said Wozniacki who made just seven unforced errors.

Earlier, Bartoli completed a swift demolition job of Peng.

The world number 18, who is unseeded in Qatar, hardly gave Peng a chance to find her footing in another hopelessly one-sided match to stay on course for a possible sixth title on the WTA Tour.

Bartoli, who had sent eighth seed Shahar Peer packing in the second round earning praise from the Israeli, was again ruthless, her trademark double-handed shots on either side often leaving her Chinese rival stranded.

She hit four aces and 22 winners, committing just nine unforced errors compared to Peng's 18.

"I'm pleased with my level of play," said the Frenchwoman. "I'm moving much better on the court compared to the previous years and I hope to continue playing like this."

Bartoli also had words for her father and coach Dr Walter Bartoli. "I am thankful to my dad for his training and guidance," said the 2007 Wimbledon finalist.

Hantuchova, who won the title in Pattaya City earlier in the month, had gotten to the quarter-finals after rallying from a set down in both her previous matches and it appeared she would pull off a similar feat before Zvonareva got her act together.

Trailing 5-4 in the third set, Zvonareva broke Hantuchova for the first time in the 10th game to level the scores and then went on to win the next two to emerge victorious in three hours and nine minutes.

This was Zvonareva's fifth win in seven matches against Hantuchova, but the Russian had lost their two previous - in Pattaya earlier this month and Cincinnati in 2009.