World No 1 Nelly Korda held her nerve and weathered a literal storm to clinch the Olympic title on Saturday as the United States earned a sweep of the golf gold medals at Tokyo 2020.
Korda, who won her first major at the Women's PGA Championship in June, shot a final-round 69 to finish at 17-under-par 267 and win by one stroke ahead of Lydia Ko of New Zealand and Japan's Mone Inami.
Inami secured a silver medal for the host nation at the first extra hole play-off when Ko missed a 10-foot putt for a par.
That went some way to making up for the agony suffered by golf fans in Japan six days ago when Masters champion Hideki Matsuyama missed out on a bronze medal in a seven-man playoff on the same Kasumigaseki Country Club course.
US world No 4 Xander Schauffele, who won the men's competition last week, tweeted a message of support for Korda, urging her to "bring home the gold".
But she had to sit out a late break for "dangerous weather" and hold off the charging pair of Inami and Rio 2016 silver medallist Ko, who both carded superb six-under par rounds of 65 to put her under immense pressure.
After almost an hour's suspension because of the storm, Inami sank a birdie putt at the 17th green to move into a tie for the lead. But the world No 28 buried her approach into the face of a greenside bunker to drop a crucial shot when a par at the last would have forced a playoff for gold.
Ko, playing in the final group with Korda, had an eagle putt at the 17th from just off the green to make it a three-way tie at the top. She could not make it but the birdie took her to 16-under and a par at the last meant she became the first golfer to win two Olympic medals.
Korda was embraced by her ecstatic sister and fellow Team USA player Jessica after she tapped in on the final green for gold.
"Obviously I was nervous, but during the rain delay I was just with my sister, we were relaxing, kind of chit-chatting on the ground, in the clubhouse," she said.
"I think that really helped a lot just to kind of not think about it and just to kind of take a step away in a sense during that rain delay and have some fun."
The final group of Korda, Ko and India's Aditi Ashok teed off early at 8.18am local time, three hours ahead of the original schedule, in an attempt to complete the full 72 holes before a tropical storm hit.
They kept Korda under immense pressure, with Inami in the group ahead setting the pace, but the ice-cool American managed to repel them all.
There was heartbreak over the closing holes for India's 23-year-old Ashok. For much of the week she had been in the medal positions but could not find the birdie she needed to make it a three-way fight for silver and bronze.
Ashok carded her fourth consecutive round in the 60s, but her three-under 68 was only good enough for solo fourth place at 15-under par 269.
"I didn't leave anything out there, I think I gave it my 100 per cent," said Ashok, the world No 200. "But, yeah, fourth at an Olympics where they give out three medals kind of sucks."