Demolition mode  ... Caroline Wozniacki gets airborne in Sydney on Sunday.

Demolition mode ... Caroline Wozniacki gets airborne in Sydney on Sunday. Photo: Reuters

Last time Caroline Wozniacki was in Sydney, she was the world No.1.

But having dropped to the cusp of the top 10 and still searching for her maiden grand slam, the 22-year-old returns to Australia with less pressure but the same expectation.

She breezed through her opening-round match at the Sydney International in about an hour, accounting for her close friend Urszula Radwanska 6-1, 6-2 in sweltering heat at Sydney Olympic Park.

Rapt  ... Dominika Cibulkova after her first-round win.

Rapt ... Dominika Cibulkova after her first-round win. Photo: AFP

The Australian Open was her most successful grand slam last year, reaching the quarter-finals.

She bowed out in the first round of Wimbledon and the US Open but the Dane insists her tennis hasn't been as bad as recent results suggest.

''I think at Wimbledon [against Tamira Paszek] I was unlucky; I think I played great tennis,'' she said. ''I had match points and could have won but it didn't go my way, and she ended up going to the quarter-finals of the tournament, so it's bad luck, that's what happens in tennis sometimes.

''At the US Open, I got a bit of a knee injury … and was struggling a little bit. I felt like I was starting to hit the ball well and I felt like it was making progress but when I went into the match, nothing went my way and that was quite disappointing because you always want to go in and compete at 100 per cent … I got to rest up a little bit after the US Open and I really worked on a few things after that, and I felt like I could be 100 per cent healthy and 100 per cent committed to the training.''

She recovered from the niggling knee injury and enjoyed a strong finish to the year, reaching the final at the year-end Tournament of Champions in Sofia, Bulgaria.

Wozniacki went down to Nadia Petrova in the decider, but believes she's in prime condition heading into the first grand slam of the year.

''I've had a great off-season,'' she said. ''I could practise 100 per cent, I feel fit. Unfortunately, I think it happens all the time, that you get sick when you have some down time and I was sick when I was on vacation for five or six days, but at least I got it out of the way before practice started and I was 100 per cent once I started practising and that's a great feeling. It's great to go to sleep at night knowing you have done everything you could to be a better player. I felt like I played really well and to finish the year the way I did with another win in Moscow and finishing off with a final in Sofia, it was a great finish.''

Meanwhile, Dominika Cibulkova upset fifth seed Petra Kvitova in a 6-1, 6-1 demolition on centre court. Russia's Maria Kirilenko was too strong for Australian wildcard Olivia Rogowska to set up a second-round clash with Italian No.3 seed Sara Errani. Samantha Stosur plays China's Jie Zheng on Monday.