World No 2 Suzann Pettersen carded an opening-day six-under-par 66 to lead the ISPS HANDA Women's Australian Open by one shot in Melbourne.
The Norwegian Solheim Cup star, winner of last year's Evian Championships, carded nine birdies and three bogeys to edge clear of a four-way tie for second at the Victoria Golf Club.
Marion Ricordeau of France, who posted eight birdies, a bogey and a double bogey, briefly joined Pettersen atop the leaderboard before slipping back alongside Hee Young Park of Korea and American duo Jessica Korda and Jaclyn Sweeney on five-under.
England's Holly Clyburn figured best of the British contingent after signing for a 68, two better than compatriot Trish Johnson and Becky Morgan of Wales.
"In the first round of the year you're always anxious to get started and it took me a while to get really comfortable and to trust what I have been working on," said Pettersen.
"In the end the trust was stronger than the rest. I hit a lot of great shots but I also have to say I left a lot of shots out there.
"I three-putted a lot of greens, stupid three-putts really, but I also felt like I played good and gave myself a lot of birdie chances.
"I really just want to see how good I can be. I know I'm good. If I play like I did today and trust my swing and trust what I'm working on, I just want to see how far I can get," added the 32-year-old, who will take over top spot in the world rankings with a first or second finish this weekend.