DUBAI, Feb 22: Former world number one Caroline Wozniacki reached the Dubai Open semi-finals on Thursday with a 4-6, 6-1, 6-4 win over Marion Bartoli, shrugging off a code violation in the process.

Wozniacki was warned for illegal coaching as the match boiled up to a thrilling finish, apparently because she was talking to her father Piotr.

“I'm not sure if it's coaching if I talk to the coach, but apparently that's new rules, so I guess that I can't say anything nowadays,” commented Wozniacki.

“I was telling him things, and all of a sudden I hear I get a code violation.    I'm like, okay.”

Then she turned the aggravation into laughter.

“I was telling him what I was doing wrong. There's not much he can say because he knows that if he says yes, then he's in trouble, and if he says no, he's in trouble too.”

Wozniacki will tackle Petra Kvitova for a place in the final after the 2011 Wimbledon champion underlined her new status as the unofficial tournament favourite by ending the title defence of Agnieszka Radwanska.

The Czech Republic player again showed that she is in her best form since winning her only Grand Slam title 19 months ago, out-hitting and out-serving the third-seeded Pole, 6-2, 6-4.

It followed her victory over former French Open champion Ana Ivanovic on Wednesday -- and her near-success against Serena Williams last week in Qatar -- and was her best win in 15 months.

“I've played three great matches so far,” said Kvitova, who believes that more fitness work with a new trainer has made an important difference to her least impressive area, her movement.

“And that's something I really need -- to play more matches this season. I hope this will help me for the rest of the year.”Roberta Vinci and Sara Errani, the world's top doubles pair, will put their lifelong friendship to one side on Friday when they clash in the other semi-final.

Vinci, who had accounted for one former Grand Slam winner and one seeded player already, beat the seventh-seeded former US Open champion, Samantha Stosur 6-2, 6-4 to reach the last four.

Errani, who had played one long three-set match already, had another, beating Nadia Petrova, the former world number three from Russia, 6-4, 0-6, 6-3.

Vinci said it would be like “playing my sister,” and Errani pointed out how strange it might feel as they spend about 300 days together during the year.

“I'm number one in the world in doubles, so it's incredible for me,” said Vinci who is ranked 17 in singles.

“I'm probably playing singles in a more relaxed way, and so I'm playing better.”She added: “It was a great match for me, great performance. I played a good game today like yesterday,” she said, referring to her straight sets win over Angelique Kerber, the fourth seed from Germany.

Results:

Quarter finals: Sara Errani (ITA x5) bt Nadia Petrova (RUS) 6-4, 0-6, 6-3; Roberta Vinci (ITA) bt Samantha Stosur (AUS x7) 6-2, 6-4; Caroline Wozniacki (DEN x8) bt Marion Bartoli (FRA) 4-6, 6-1, 6-4; Petra Kvitova (CZE x6) bt Agnieszka Radwanska (POL x3) 6-2, 6-4.—AFP