Sei Young Kim watched her 12-foot birdie putt break toward the hole and disappear into the cup, landing her in territory no one had ever been on the LPGA Tour.
She reached 30 under par in the Thornberry Creek LPGA Classic in Oneida, Wis.
And she wasn’t finished.
Kim added yet another birdie, closed with a 7-under 65 and wound up her historic week Sunday at 31 under for a nine-shot victory.
‘‘I never thought I'd shoot 31 under,’’ Kim said. ‘‘I really feel incredible.’’
She was every bit of that in a week so dominant that she now has two LPGA scoring records all to herself.
Kim’s 31 under broke by four shots to par the record she had shared with Annika Sorenstam. Kim won the 2016 Founders Cup at 27 under, while Sorenstam won the 2001 Standard Register Ping at 27 under, the tournament where the Swede shot 59.
‘‘After the Founders Cup, I got new goals,’’ she said. ‘‘I wish I could break up the [tour] record. It’s really unbelievable.’’
Kim also set the 72-hole scoring record at 257, finishing with three straight pars to break the mark by one shot.
The 25-year-old from South Korea opened with a 63, followed with a 65, and shot a 64 on Saturday to reach 24 under, which tied Sorenstam’s 54-hole record in 2003 at the Mizuno Classic in Japan, a 54-hole event.
The only blemish for Kim all week was a double bogey in the second round Friday. She had 31 birdies and one eagle, another record for most sub-par holes in a tournament. Kim hit 67 out of 72 greens in regulation.
For all the birdies, Kim set the LPGA record with a par on the final hole to finish at 257.
‘‘I had the double-bogey on 17. That was the only one I had where I missed the shot. It’s crazy,’’ Kim said.
Kim won for the first time this year and joined Brooke Henderson as the only players on the tour with at least one victory in each of the last four seasons.
PGA — Kevin Na ended a nearly seven-year winless drought on the PGA Tour, shooting a 6-under 64 for a five-stroke victory at A Military Tribute at The Greenbrier in White Sulphur springs, W. Va.
Na birdied six of his first 10 holes to open up a big lead over third-round co-leader Kelly Kraft on the Old White TPC. The 34-year-old Na cruised from there and finished at 19-under 261.
Na’s only previous tour win came in Las Vegas in October 2011.
Kraft shot 70 and finished second at 14 under.
Brandt Snedeker and Jason Kokrak tied for third at 13 under. Snedeker had a 64 and Kokrak shot 67.
Kraft, Snedeker, Kokrak, and Austin Cook earned spots in the British Open in two weeks. The leading four players not already exempt from the top-12 finishers qualified.
Phil Mickelson broke the rules again, only this time he didn’t realize it until after his violation.
Mickelson tamped down fescue grass with his foot in front of the seventh tee. He then called a two-stroke penalty on himself for improving his line of play. He finished at 1-under, tied for 65th.
European — Russell Knox rolled in almost-identical birdie putts from around 40 feet on the 72nd hole and the first playoff hole to win the Irish Open in Donegal.
After Knox made birdie on No. 18 to set the clubhouse target at 14 under par, Ryan Fox missed an 8-foot birdie putt that would have won him the Rolex Series event.
Fox, who had a 68, secured a place in the British Open at Carnoustie, Scotland, later this month.
Jorge Campillo (65) was in third place, a shot further back, and defending champion Jon Rahm was in a share of fourth after a 66.
Rory McIlroy shot 71 and was 2 under overall.