MIAMI • It was not only the most important birdie in Kim Sei-young's career but also the most lucrative in the history of women's golf.
The South Korean rolled in her long putt at the 72nd hole on Sunday evening to clinch the LPGA Tour Championship, claiming the record US$1.5 million (S$2.05 million) winner's prize.
World No. 11 Kim had struggled to build momentum in her final round at Tiburon Golf Club in Naples, Florida.
However, the overnight leader, who never relinquished her position at the top of the leaderboard throughout the season finale, came through when it mattered, edging out Charley Hull by one stroke.
She was one under for the day through the 17th hole and the 41st-ranked Englishwoman had joined her at 17 under with a bogey-free six-under 66 that included birdies at holes No. 16, 17 and 18.
A play-off looked more than possible, but Kim did not blink, rolling in her fifth birdie of the day at the final hole to seal the win with a two-under 70 for an 18-under total of 270.
A thrilled Kim later told reporters she had "no idea" that she was putting for the win at No. 18, saying: "Last putt, I was just trying to make two-putt because I didn't see the leaderboard...
"It's unbelievable. I was, like, so emotional, almost crying."
Hull, who started the day five shots off the pace, said she knew after birdies at the second, 12th and 13th that she had a shot at the largest winner's cheque in women's golf.
"Kind of 15, I looked at the board and thought I've got a chance," she said. "I didn't birdie 15, but birdied 16, 17, 18 - I gave it my best shot."
Even more than the prize money, Kim also expressed how it had been "most satisfying" after fulfilling her pre-season goals, with her third title of the year adding to a resume that now includes 10 Tour victories.
Compatriot and world No. 1 Ko Jin-young finished joint-11th, but still snagged the money title with US$2.77 million and the Vare Trophy for the lowest scoring average.