Defending champion Kim Clijsters and top seed Caroline Wozniacki began their quest for the Australian Open title with comfortable straight-set wins.
Wozniacki showed no ill effects from a troubling wrist injury as she overcame Anastasia Rodionova 6-2 6-1.
Defending champion Clijsters began her defence with a 7-5 6-1 victory over qualifier Maria Joao Koehler.
There were first-round victories too for Agnieszka Radwanska and last year's runner-up Li Na.
Radwanska, who has a chance of claiming the top ranking over the next fortnight, survived a stern three-hour test from Bethanie Mattek-Sands to win 6-7 (10-12) 6-4 6-2 and set up a meeting with Argentine Paula Ormaechea.
Fifth seed Li Na made light work of Ksenia Pervak with a 6-3 6-1 victory.
There had been rumours during the build-up to the opening day at Melbourne that world number one Wozniacki had been wincing in practice, but she showed no discomfort during a routine opening victory.
"It feels much better," said Wozniacki after completing victory in one hour and 16 minutes at the floodlit Rod Laver Arena.
"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."
Clijsters, who could meet Wozniacki in the quarter-finals, made a jittery start to her campaign, but improved as the match progressed to set up a meeting with Stephanie Foretz.
A thigh injury had forced the Belgian to miss the Brisbane International two weeks ago, but afterwards Clijsters said she was "feeling good", insisting her injury worries were behind her.
"I don't think anybody plays a grand slam playing seven perfect matches," added Clijsters. "You have to fight your way through it sometimes and find that little extra on the most important points."
Russia's Nina Bratchikova caused the biggest upset of the day, defeating the 19th seed, Italy's Flavia Pennetta, 6-3 1-6 6-2.
The Italian, who injured her back in the season-opening tournament in Auckland, battled and showed some resistance until eventually succumbing after one hour and 30 minutes.
Other winners included the 20th seed Daniela Hantuchova, a 4-6 6-3 6-2 winner against Varvara Lepchenko, and 22nd seed Julia Goerges who beat Polona Hercog 6-3 7-6 (7-3).