World number one Simona Halep gained revenge on Kaia Kanepi in a compelling three-set battle on Margaret Court Arena.
Halep lost to Kanepi in the first round of the US Open last August then remarkably drew the powerful Estonian again here.
It looked like a repeat upset was on the cards when Kanepi took the opening set on a tie-break, but Halep converted her fourth set point in the 10th game of the second and went on to win 6-7 (2) 6-4 6-2.
The victory ended a five-match losing streak for the top seed, who was troubled by a back problem at the end of last season.
The Romanian, the runner-up 12 months ago, said: "I don't want to remember about that match (in New York) because it was a tough one. I knew she's a very tough opponent. It was good for me tonight and I'm really happy I can play the second round."
