France's Yannick Agnel won his second gold of London 2012, taking victory in the men's 200m freestyle as American Ryan Lochte finished fourth.
Agnel, who helped France win the 4x100m freestyle relay, led from the front and finished two metres clear in one minute, 43.14 seconds.
"Agnel is head and shoulders ahead of the rest of the field. To win by that distance doesn't happen often especially in this event. That's two medals for him now which is a fantastic achievement."
South Korea's Park Taehwan and China's Sun Yang shared the silver, while Britain's Robbie Renwick was sixth.
"If I keep going, in four years I might get a medal," Renwick said.
"It was a solid performance so I couldn't ask for much more. I can't believe it went so fast but it was a good race for me.
"The home support was amazing."
Agnel's gold was France's third in the Aquatics Centre and it underlined the 20-year-old's supreme talent. Once he eked out a gap, he swam away from his rivals. Lochte was second after 150m, but the American faded down the final length.
Park, who had slipped behind 400m individual medley winner Lochte, finished strongly as Sun broke through to share second place.