The 25-year-old, long considered perhaps the best woman player never to win one of the five majors, got rid of that unwanted tag with a fantastic display at Aix-les-Bains which saw her shoot a flawless final round seven-under 64 and then win a sudden death play-off at the first hole.

Coming from a record-equalling seven shots back on Sunday, she caught up with the week's stand out performer, South Korea's Jeongeun Lee6 as the pair both finished on an 18-under par total of 266.

"I just played to the best of my ability and it's really great to win a major. It's just really amazing," said Lee, after being doused in bubbly by pal Lydia Ko and then taking a swig of champagne herself on the 18th green to celebrate her triumph.

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"I never really thought about winning while I was playing. I just tried to make as many birdies as I could. I think I only saw the leaderboard once or twice."

Lee is doused in bubbles by friend and fellow major winner Lydia Ko. PHOTO: Stuart Franklin/Getty Images.

It had been an amazing final day with Lee, Lee6 and teenage American Yealimi Noh all battling for the title, although the Australian had initially no thoughts of joining Karrie Webb, Jan Stephenson and Hannah Green in the Aussie major winners circle.

Still, she set the pace with her seven birdies and a superb par-saving putt at the 17th to keep her challenge on track.

At the 18th, Lee drove into the trees, but pitched out and got up-and-down for a fourth birdie in five holes, briefly holding a two-shot lead to put all the pressure on her pursuers.

Lee6 had suffered a meltdown to see her overnight five-shot lead over Noh – and seven over Lee – disappear but fought back courageously at the end of her round with three closing birdies.

Yet Lee, who'd played the best golf over the weekend with a 65 on Saturday and 64 on Sunday, was nerveless at the first playoff hole, drilling her six-iron second at the par-five 18th to within eight foot of the pin. It proved a glorious tournament winner.

For the pressure was all on Lee6, who caught her second shot thin to find the lake in front of the green, leaving Minjee with three putts to take the title as she finished with a closing birdie.

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She lipped out for what would have been a fitting eagle finish but was all smiles as added her victory to younger brother Min Woo Lee's win on the men's European Tour in the Scottish Open a fortnight earlier.

Lee reckoned her family would all be watching and she had an emotional message for them.

"I'm sure they're watching, I just want to thank them for everything, they've sacrificed so much for me. I know they're really happy, and I am too!"

Previously a five-time winner on the LPGA Tour but without a win on the circuit for two years, the world's former No.1 amateur has been thought of as the next major winner from Australia, following Green's 2019 KPMG Women’s PGA Championship victory.

There was a remarkable serenity about the way she went about her business on Sunday, even as she came into the playoff.

After a perfect drive at the play-off hole, she faced 173 metres to the pin across the water and was determined to go with a 5-iron approach.

"I had a bit of adrenaline," she smiled. "I actually said 5-iron' but Gilly (her caddie Jason Gilroyed) said 'six' – so I went with the 6-iron. Thank you, Gilly!"

Extraordinarily, Lee's round wasn't even the best of the day. That honour went to Ireland's Leona Maguire, whose 10-under 61 tied the lowest round ever by a female or male in a major – two days after Lee6 had done the same in the second round.

- Ian Chadband, Australian Associated Press