While American Katie Ledecky and Australian Elijah Winnington gained redemption for Tokyo Olympic disappointment, young Frenchman Leon Marchand made clear he had Paris on his mind after a scorching medley on the first evening of the World Swimming Championships Saturday in Budapest.
In the 400m freestyle relays, the Olympic champions continued their domination as the US men and Australian women both won with a second to spare.
Marchand outdid his father Xavier, a world medley silver medallist in 1998, as he won with the second-fastest men's 400m medley time in history.
The 20-year-old finished in 4min 4.28sec, just over a third of a second outside the record set by Michael Phelps in Beijing in 2008.
American Foster Carson, 20, was second at 2.28sec with US Olympic champion Chase Kalisz was third.
"I didn't know it would be that fast," a delighted Marchand told the press conference.
He said he had been aiming for his home Olympics in two years. "That was my goal for Paris: under 4.05."
Marchand moved from his native Toulouse to the United States after last summer's Olympics to swim for the Arizona State University team coached by Bob Bowman, who mentored Phelps.
The switch worked.
"I improved a lot in backstroke and breaststroke," Marchand said.
"I'm very excited for Mike because I'm very close to his record."
He said he had not yet met Phelps but "I talked to him by message."
Marchand trailed Carson through 200m before unleashing a sizzling breaststroke which he had kept under wraps in the morning heats.
He started the final freestyle leg a second inside the world record before fading.
He was also almost 19 seconds faster than his father's time in the worlds in 1998.
"My dad supports me every day," he said. "I'm very happy to bring him this medal."
- 'It feels good' -
Ledecky, 25, had been eclipsed in the women's 400m freestyle by Australian Ariarne Titmus, who took her world title in 2019, her Olympic title last year and her world record last month.
With Titmus focussing on the Commonwealth Games, Ledecky broke her own world championship record as she held off a determined challenge from Canadian 15-year-old Summer McIntosh to collect a 16th world championship gold
"It feels good," Ledecky said.
McIntosh became the third woman to dip under four minutes in a textile suit. American Leah Smith took bronze in 4:02.08.
"Summer is now in the sub-4 minute club, I will have my work cut out for me, these races are only going to get harder," said Ledecky.
In the men's 400m, Winnington won in 3:41.22, the fastest time in the event in a decade, to edge German Lukas Martens by 1.63sec with Brazilian Guilherme Pereira da Costa third.
Winnington, 22, had gone to the Olympics as the favourite, but slumped to seventh in a final won by surprising Tunisian Ahmed Hafnaoui of Tunisia, who did not enter Saturday's event.
"I wasn't focusing on results," Winnington said after his win.
"You probably saw me walking out," he said.
"I was looking around and just enjoying the experience, it's my first world championships, my second international individual final apart from Olympics, so this time around I just wanted to enjoy it and clearly just enjoying it brings out the best in me."
In the men's 400m relay, the US only started Caeleb Dressel and Brooks Curry from the quartet who won in Tokyo but left Australia trailing in second with Italy third.
"First place is always good," said Dressel.
Only Meg Harris remained from the Australian 400m relay team that set a world record in the Olympics. They were still too strong for second-place Canada and third-place United States.
"This team was just as competitive as last year, you can see that from the results," said Harris.
Sunday's competition will offer four finals.
They include Dutchman Arno Kamminga trying to pull out of absent Adam Peaty's shadow in 100m breaststroke, Nicholas Santos chasing gold at 42 in the 50m butterfly and Hungarian veteran favourite Katinka Hosszu seeking an unlikely repeat of her 200m medley world title before her raucous and adoring fans.