Perth: Petra Kvitova landed a psychological blow in her battle with Caroline Wozniacki for the world number one ranking with a gripping three-set victory at the Hopman Cup on Thursday that helped Czech Republic to beat Denmark and reach the final.

Kvitova will dethrone Wozniacki as the queen of women's tennis if she wins the Sydney International next week. Her powerful but occasionally erratic 7-6 3-6 6-4 win at the Burswood Dome was the ideal build-up to the Sydney tournament and, even more importantly, the Australian Open from January 16.

Kvitova and team mate Tomas Berdych stormed into the final of the mixed team event as Group A winners with a 2-0 defeat of Denmark.

Berdych sealed the tie, and a date with Group B winners France in Saturday's final, by beating Frederik Nielsen 6-1 6-3.

Wozniacki was clearly not optimistic about Denmark's chances of beating the Czechs and reaching the final as she had booked an overnight flight to Sydney before the tie began.

Wozniacki's critics say she does not deserve the top ranking because she has not yet won a major title. Kvitova lifted the Wimbledon trophy last year and went on to win the prestigious season-ending WTA Championships in Istanbul, defeating Wozniacki along the way.

The world number two said her preparations for the Australian Open were going perfectly.

"I'm really happy that I won because it was a little, small test of how we are prepared for the Aussie Open," Kvitova said.

"Caroline played really well, it was a close match, but every match is different and it is not the Aussie Open. I understand that people like seeing numbers one and two in the world playing and I hope it was a good match for them to watch.

"It's the first time we have gone to three sets in a match. I was slow in the second set but I needed to be more aggressive. The key was my serve. That was the key for the whole match."

Wozniacki, who started slowly at the Hopman Cup after arriving late following a holiday in Thailand, said: "I'm not feeling any pressure about the ranking.

"I've finished number one for two years in a row and I think that's a great achievement. Very few people have ever done that. I'm playing well and enjoying my tennis and I'm excited a new year is starting.

"It was a great match from both of us, it could have gone either way. I feel like my form is starting to go on the up. All I can do is keep focused and win as many matches and tournaments as possible.

"We have just over a week before the Australian Open starts - I think I've got a lot to look forward to."