World number one Caroline Wozniacki dispelled any lingering doubt about her wrist injury by brushing aside the challenge of Anastasia Rodionova at the Australian Open today.

The Dane injured the joint during her defeat by Agnieszka Radwanska at the Sydney International last week and there were reports she had been wincing in practice as recently as yesterday.

But there were few signs of discomfort as she crushed Australian Rodionova 6-2 6-1 in one hour and 16 minutes.

Afterwards she said: "It (the wrist) feels much better. I was a bit nervous before the match as I didn't really know what to expect but I am very happy with the way I felt out there.

"When I got into my rhythm and started to play more comfortably it paid off."

Wozniacki's late-night victory capped a good opening day for the seeded women after Victoria Azarenka earlier led a quintet of top-ranked players in cruising into the second round.

Azarenka, the third seed, thrashed Britain's Heather Watson in a ruthless display on Rod Laver Arena to join defending champion Kim Clijsters, last year's beaten finalist Li Na, eighth seed Agnieszka Radwanska and 10th seed Francesca Schiavone in posting victories.

Azarenka dropped the opening game to the 19-year-old from Guernsey but then ran through the next 12 to secure a 6-1 6-0 win.

The Belarusian was satisfied with her display after only arriving in Melbourne at the weekend following her win in Sydney.

She said: "The score looks easy but to play the match is never easy, especially for me coming here only on Saturday.

"I only hit once before the match and the first time I hit on centre court was this morning.

"So I think it was a good performance but there are still a few things I have to work on to be better in the second round."

Azarenka is among the favourites for the title but she dismissed talk of breaking through and winning her first grand slam crown, adding: "I am not really approaching it that way, I'm approaching it day by day because every day is different.

"Sometimes you feel great, sometimes you feel sleepy and sometimes you feel crazy energetic. It's really important how well you take each moment."

Clijsters looked rusty in her win over Maria Joao Koehler, a qualifier from Portugal.

The 11th-seeded Belgian missed the majority of the second half of last season through injury and then had to pull out of the Brisbane International warm-up event with a hip injury.

And her usual fluency was lacking although she managed to advance courtesy of a 7-5 6-1 triumph.

"I really felt like I had to find my rhythm out there," she said. "But once I did I felt I was in charge most of the time.

"I don't think anybody plays a grand slam playing seven perfect matches. You have to fight your way through it sometimes and find that little extra on the most important points."

Li, who became the first Asian player to win a grand slam when she claimed the French Open crown last June, beat Ksenia Pervak 6-3 6-1, Schiavone saw off Laura Pous-Tio 6-1 6-3 and Radwanska edged out American Bethanie Mattek-Sands 6-7 (10/12) 6-4 6-2.