Caeleb Dressel of the United States became the first swimmer to win three gold medals in a single evening at the world championships after producing a trio of storming performances on Saturday.
Dressel's sprint heroics were compiled in just under two hours, interspersed by Sarah Sjostrom's world record in the women's 50 metres freestyle on another stunning night's racing at the Duna Arena.
With the men's 4x100m medley to come, he needs one more title to draw level with Michael Phelps's record of seven golds at the 2007 championships.
“It was physically challenging, mentally straining with lots of emotional energy,” Dressel said of his night's work. “You have to enjoy the moment and refocus very quickly.”
Dressel began his historic evening in the men's 50m freestyle, posting a world textile best time of 21.15 seconds. Brazil's Bruno Fratus took silver, 0.12 seconds back, with Ben Proud of Britain snatching bronze.
“I don't consider myself a talented guy, but I'm sure a hard worker,” said Fratus.
The 20-year-old Dressel then had 33 minutes to ready himself for the men's 100m butterfly.
He never trailed and delivered two lengths of sizzling pace in 49.86 seconds. Edging ever closer to Phelps's 2009 world record, he finished 0.04 seconds shy of the eight-year-old mark.
“I honestly didn't expect to be that close,” Dressel told reporters.
Dressel's speed, coupled with the sheer noise inside the arena, clearly lifted Kristof Milak of Hungary who posted a world junior record time for silver.
Milak touched 0.76 seconds behind Dressel, while Singapore's Olympic champion Joseph Schooling shared bronze with James Guy of Britain.
After just over an hour to recover, Dressel then led the US quartet out in a world-record rout in the 4x100 metres mixed freestyle relay.