Seventeen-year-old Lydia Jacoby made history Tuesday in Tokyo by upsetting defending champion Lilly King to earn Olympic gold for the U.S. in the women’s 100-meter breaststroke.

Video taken from a watch party at a railroad terminal in her scarcely populated hometown in Seward, Alaska, captured hundreds of people erupting into cheers following her win at the Summer Games. 

Jacoby was the first swimmer from Alaska to make the U.S. Olympic swimming team. She was shown the video of the fans in Seward and called their support "amazing."

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"A lot of big-name swimmers come from big, powerhouse clubs,'' Jacoby said, according to ESPN. "Me coming from a small club, in a state with such a small population, really shows everyone that you can do it no matter where you're from.''

Alaska Sen. Lisa Murkowski also tweeted her congratulations following the monumental feat. "This high school student from Seward, Alaska makes the whole nation proud," she wrote. 

Jacoby rallied in the race to win gold in 1 minute, 4.95 seconds. South Africa’s Tatjana Schoenmaker won silver in 1:05.22, while King, another American, earned bronze in 1:05.54 – her first defeat in a 100-meter breaststroke final in nearly five years. 

Team USA had been off to a sluggish start Tuesday, earning just a pair of bronze medals before the high schooler's shocking win. When Jacoby reached the finish line, she was captured looking at the scoreboard in apparent disbelief. 

Lydia Jacoby, of the United States, reacts after winning the final of the women's 100-meter breaststroke at the 2020 Summer Olympics, Tuesday, July 27, 2021, in Tokyo, Japan. (AP Photo/Petr David Josek)

Lydia Jacoby, of the United States, reacts after winning the final of the women's 100-meter breaststroke at the 2020 Summer Olympics, Tuesday, July 27, 2021, in Tokyo, Japan. (AP Photo/Petr David Josek)

"I was definitely racing for a medal. I knew I had it in me," Jacoby said. "I wasn’t really expecting a gold medal, so when I looked up and saw the scoreboard it was insane."

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Now, she’s heading back to Seward, — population: 2,773 — with a gold medal.

King appeared content with bronze. After the race, she stood next to her teammate and praised her for keeping gold in the USA family.

"This kid just had the swim of her life and I am so proud to be her teammate," King said.

Lydia Jacoby of the United States waves after winning the final of the women's 100-meter breaststroke at the 2020 Summer Olympics, Tuesday, July 27, 2021, in Tokyo, Japan. (AP Photo/Matthias Schrader)

Lydia Jacoby of the United States waves after winning the final of the women's 100-meter breaststroke at the 2020 Summer Olympics, Tuesday, July 27, 2021, in Tokyo, Japan. (AP Photo/Matthias Schrader)

On the men's side, the U.S. team lost a backstroke race at the Olympics for the first time since 1992.

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Russia swept the top two spots in the 100-meter back Tuesday, with Evgeny Rylov claiming the gold medal in 51.98 and teammate Kliment Kolesnikov taking the silver in 52.00.

Defending Olympic champion Ryan Murphy settled for the bronze in 52.19.

It was the first backstroke defeat for the U.S. men at the Olympics since the Barcelona Games. They won 12 straight golds at the last six Olympics, including Murphy’s sweep of the 100 and 200 back at the 2016 Rio Olympics.

World record-holder Kaylee McKeown gave the Aussie women another gold medal with a victory in the women’s 100 backstroke, setting an Olympic record.

Her winning time of 57.47 was just off the world mark she set this year of 57.45. The silver went to Canada’s Kylie Masse in 57.72, while former world record-holder Regan Smith of the United States grabbed the bronze at 58.05.

Coming into these Olympics, Australia had not won an individual women’s title since 2008. They've already got two in Tokyo, with McKeown’s gold coming after Ariarne Titmus’ victory Monday in the 400 freestyle.

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Britain went 1-2 in the men’s 200 freestyle. Tom Dean captured the gold in 1 minute, 44.22 seconds, while teammate Duncan Scott picked up the silver in 1:44.26. The bronze went to Brazil’s Fernando Scheffer at 1:44.66.

American Kieran Smith settled for a sixth-place showing after capturing a bronze in the 400 free.

Titmus and Katie Ledecky both advanced to Wednesday’s final of the 200-meter freestyle, setting up another showdown after their thrilling race in the 400 free.

Titmus was the top qualifier in the 200 semis at 1:54.82, while Ledecky -- the defending Olympic champion -- cruised to the third-best time in 1:55.34. The Aussie Terminator will be looking for her second straight gold after rallying to beat Ledecky in the 400 free.

Ledecky had a relatively easy day compared to Monday when she raced three times for a total of 2,100 meters.

"I was still a little tired the last 15," Ledecky said, "but I felt like I had good control of the heat."

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She'll have another big morning Wednesday when she competes in the finals of the 200 free and the 1,500 free — her shortest and longest events — about an hour apart.

"It’ll be a good challenge," Ledecky said. "It’s been fun to train for both of them."

The Associated Press contributed to this report