TOKYO >> Alaska, of all places, has an Olympic champion at the pool.

Seventeen-year-old Lydia Jacoby gave the United States a victory in the women’s 100-meter breaststroke, knocking off teammate and defending champion Lilly King on Tuesday.

Jacoby was the first swimmer from the Arctic state ever to make the U.S. Olympic swimming team.

Now, she’s heading back to giddy Seward, Alaska — population: 2,773 — with a gold medal, rallying to win in 1 minute, 4.95 seconds..

South Africa’s Tatjana Schoenmaker claimed the silver in 1:05.22, while King gave the Americans another medal by taking the bronze in 1:05.54.

Jacoby’s stunning win salvaged what had been a disappointing morning for the American team. The U.S. had only managed a pair of bronze medals before the high schooler came through.

Jacoby was only third at the turn, trailing Schoenmaker and King. But, with her head bobbing furiously out of the water, the teenager surged past King and glided past the South African on the final two strokes to touch first.

Looking at the scoreboard with a bit of disbelief, the enormity of her accomplishment finally hit when Schoenmaker reached across the lane rope for a hug. Then it was King bounding over from two lanes away to congratulate America’s new breaststroke queen.

“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.”

Her teammate, King, who rose to fame with her swimming prowess and outspoken views on doping in sports, was content with the bronze.

“I’m so excited for Lydia,” King said. “I love to see the future of American breaststroke coming up like this and to have somebody to go at it head to head in the country. I definitely knew she was a threat and saw a lot of myself in her effort.”

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

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.

“Winning an Olympic gold medal means you’re the best in the world,” Murphy said. “Being third in the world is no slouch.”

Along with the Russia, it was good morning for Australia and Britain.

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.

“My legs were definitely hurting with the last 20 to go,” McKeown said. “I’m sure it would have been pretty noticeable on the TV. But you know I’ve trained for that and I knew I had a really strong backend and a really good chance to be on the podium.”

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.

Dean’s victory was even more remarkable considering he has twice been stricken with COVID-19 during the buildup to the games.

“It was quite tough,” he said. “It was tough having a lot of time out the water. And obviously it requires a slow buildup because of the nature of the disease. So it’s tough and it was a very bumpy ride this season.”

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

Defending 200 free champion Sun Yang was banned from the Tokyo Olympics for a doping violation. He is serving a more than four-year ban, though he could be eligible to return for the 2024 Paris Games.

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.”

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 a hour apart.

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