Hungarian teenager Kristof Milak has shattered Michael Phelps' 10-year-old world record in the 200m butterfly.
Milak won gold in a time of 1:50.73 at the world swimming titles in South Korea, lopping 0.78 seconds off Phelps' 1:51.51 set in Rome in 2009.
"It's a tremendous honour to set such a great record," he said.
"Until 14 I was a backstroker and later I focused on the butterfly. But earlier I only did 100 metres because I wasn't strong enough."
There can be no question about his strength now.
At 19, Milak is the youngest winner of the 200-metre butterfly since Phelps triumphed as an 18-year-old in 2003, the second of the American great's five world titles in the event.
"When I turned back and saw the time, all the pressure, all the tension just got off my back and all the joys came out," Milak said.
Chad le Clos of South Africa was out under world-record pace through the first lap before Milak gained the lead after 150 metres.