The 15-year-old McIntosh clocked 2:05.20 – a world junior record – in the 200 butterfly to pip the three Olympic medalists to the title.
“It’s one of my biggest dreams in the swimming world to become world champion, and especially to do it in 200 fly is something I have always wanted to do because this is one of my favorite events,” said McIntosh, who finished 0.88 seconds ahead of American Hali Flickinger and 1.12 ahead of China’s Zhang Yufei. American Regan Smith was 1.59 behind in fourth.
Popovici, who set a world junior record of 47.13 in qualifying for the 100, had to fight hard to edge France’s Maxime Grousset by 0.06 seconds in the final with a time of 47.58.
Canada’s Joshua Liendo Edwards, who was leading at the halfway stage, took the bronze.
Two-time defending champion Caeleb Dressel didn't race after withdrawing from the rest of the competition with an unspecified medical condition earlier Wednesday.
The Americans had to wait until the women's 4x200 freestyle for their 11th gold of the championships as Claire Weinstein, Leah Smith, Ledecky and Bella Sims finished 2.41 seconds ahead of the Australian team and 3.31 ahead of the Canadians.
McIntosh showed no ill effects from the 200 butterfly earlier as she set a junior record of 1:54.79 over her 200 meters. Only Ledecky and Sims were faster on the night.
“I am so proud,” Ledecky said. “I think I realized when we were on the medal podium it had been a while since we had all been up there singing the national anthem together; trying to hit those high-pitched notes together. So that was a lot of fun.”
Alex Walsh and Flickinger will also get gold medals for their swims on the relay during prelims.
Only the U.S. (11 gold, six silver, nine bronze) and Australia (two gold, five silver, one bronze) have won at least one medal on each of the five nights of the swimming competition.
Kylie Masse claimed Canada’s second gold of the night by winning the women’s 50 backstroke in 27.31 – 0.08 ahead of American Katharine Berkoff and 0.09 ahead of French swimmer Analia Pigree.
Masse became the first swimmer from Canada, male or female, to win three golds at a worlds.
The 20-year-old Léon Marchand then continued his remarkable competition by winning the men’s 200 individual medley in 1:55.22, lowering the French record he set in the semifinals.
Marchand finished 0.49 ahead of American Carson Foster, 1.00 ahead of Japan’s Daiya Seto and 1.21 ahead of Chase Kalisz.
It was Marchand's second gold at this worlds after the men's 400 medley on Saturday, when he almost took Michael Phelps' world record, and his third medal after silver in the 200 butterfly on Tuesday.
“I was a little tired this morning,” Marchand told journalists.
___
More AP sports: https://apnews.com/hub/sports and https://twitter.com/AP_Sports
David Popovici of Romania answers questions to journalists after winning the men's 100m freestyle final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
David Popovici of Romania answers questions to journalists after winning the men's 100m freestyle final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Credit: Petr David Josek
David Popovici of Romania, right, celebrates after winning the Men 100m Freestyle final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
David Popovici of Romania, right, celebrates after winning the Men 100m Freestyle final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Credit: Anna Szilagyi
Silver medalist Maxime Grousset of France, left, gold medalist David Popovici of Romania, centre, bronze medalist Joshua Liendo Edwards of Canada, right, pose with their medals after the Men 100m Freestyle final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Silver medalist Maxime Grousset of France, left, gold medalist David Popovici of Romania, centre, bronze medalist Joshua Liendo Edwards of Canada, right, pose with their medals after the Men 100m Freestyle final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Credit: Petr David Josek
Silver medalist Hali Flickinger of the United States, left, gold medalist Summer Mcintosh of Canada, centre, bronze medalist Yufei Zhang of China, right, pose with their medals after the Women 200m Butterfly final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Silver medalist Hali Flickinger of the United States, left, gold medalist Summer Mcintosh of Canada, centre, bronze medalist Yufei Zhang of China, right, pose with their medals after the Women 200m Butterfly final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Credit: Petr David Josek
Summer Ncintosh of Canada answers questions to journalists after winning the women's 200m Butterfly final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Summer Ncintosh of Canada answers questions to journalists after winning the women's 200m Butterfly final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Credit: Petr David Josek
Summer Ncintosh of Canada competes to win the women's 200m Butterfly final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Summer Ncintosh of Canada competes to win the women's 200m Butterfly final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Credit: Petr David Josek
Leon Marchand of France reacts after the Men 200m Medley final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Leon Marchand of France reacts after the Men 200m Medley final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Credit: Anna Szilagyi
Leon Marchand of France answers questions to media after winning the men's 200m individual medley final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Leon Marchand of France answers questions to media after winning the men's 200m individual medley final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Credit: Petr David Josek
Silver medalist team of Australia celebrate after the Women 4x200m Freestyle Relay final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Silver medalist team of Australia celebrate after the Women 4x200m Freestyle Relay final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Credit: Anna Szilagyi
Bronze medalists team of Canada pose with their medals after the Women 4x200m Freestyle Relay final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Bronze medalists team of Canada pose with their medals after the Women 4x200m Freestyle Relay final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Credit: Anna Szilagyi
Gold medalist Leon Marchand of France pose with his medal after the Men 200m Medley final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Gold medalist Leon Marchand of France pose with his medal after the Men 200m Medley final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Credit: Petr David Josek
Team of United States celebrate their victory in the Women 4x200m Freestyle Relay final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Team of United States celebrate their victory in the Women 4x200m Freestyle Relay final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Credit: Anna Szilagyi
Gold medalists team of United States celebrate their victory after the Women 4x200m Freestyle Relay final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Gold medalists team of United States celebrate their victory after the Women 4x200m Freestyle Relay final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Credit: Anna Szilagyi
Gold medalist team of United States pose with their medals after the Women 4x200m Freestyle Relay final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Gold medalist team of United States pose with their medals after the Women 4x200m Freestyle Relay final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Credit: Anna Szilagyi
Bronze medalist Daiya Seto of Japan poses with his medal after the Men 200m Medley final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Bronze medalist Daiya Seto of Japan poses with his medal after the Men 200m Medley final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Credit: Petr David Josek
Silver medalist Carson Foster of the United States poses with his medal after the Men 200m Medley final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Silver medalist Carson Foster of the United States poses with his medal after the Men 200m Medley final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Petr David Josek)
Credit: Petr David Josek
Credit: Petr David Josek
Silver medalists team of Australia, left, gold medalist team of United States, centre, bronze medalist team of Canada, right, pose with their medals after the Women 4x200m Freestyle Relay final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Silver medalists team of Australia, left, gold medalist team of United States, centre, bronze medalist team of Canada, right, pose with their medals after the Women 4x200m Freestyle Relay final at the 19th FINA World Championships in Budapest, Hungary, Wednesday, June 22, 2022. (AP Photo/Anna Szilagyi)
Credit: Anna Szilagyi
Credit: Anna Szilagyi
