Oliver Hynd became Paralympic champion in the SM8 200 metres individual medley with an unstoppable performance tonight at the Aquatics Centre.
The 17-year-old has enjoyed a superb Paralympic debut and came into the race with a silver and bronze already from the meet.
Fourth after the opening butterfly leg, Hynd moved through the field on the backstroke to turn second at halfway.
The Nova Centurion swimmer had moved into first with 50m to go and his opponents made no headway as the Briton clocked two minutes 24.63 seconds for victory.
Brother Sam was just out of the medals in fourth.
Hynd was stunned by his gold.
"I don't believe it - it's amazing," he told Channel 4.
"When I touched I didn't really want to believe it. I thought 'it can't be right' but I'm Paralympic champion and I'm over the moon.
"This has just been amazing."