Fifteen-year-old schoolboy swimming sensation Josef Craig has smashed the world record to became Britain's youngest Paralympic gold medal winner - and declared: "It's the happiest day of my life."
He appeared overcome with emotion after storming to gold in front of a roaring aquatics centre crowd.
Craig, who has cerebral palsy, broke the world record he set in his heat this morning by comfortably winning the 400m final.
Speaking after the win, he said: "I genuinely didn't think this would happen. I thought, it's the last 400m of the season, it doesn't matter if I die at the end, just go for it, it doesn't matter.
"I didn't realise that I'd broken the world record, I didn't think I had it in me. But obviously because of this great crowd again and all this support, I managed to. It means more than anything in the world. It's the happiest day of my life.
The South Shields teenager, who was struck down with Grave's disease last year, a thyroid condition which causes substantial weight loss, was widely tipped to succeed at the Rio games in 2016, but stunned everyone with his dramatic win.
Speaking straight after the race, his beaming mum Kim said: "I watched him from the poolside. I think I am about to pass out. I am so proud."
ParalympicsGB have now smashed through the 100 medal barrier - beating their haul in Beijing and just three away from their pre-games target. The total includes 28 golds, 37 silver and 35 bronze.
The win comes on the day cyclist Sarah Storey cemented herself in the Paralympic hall of fame by equalling Tanni Grey-Thomson's haul of 11 gold medals. Storey won her fourth gold of London 2012 in a sensational road race at Brand's Hatch and was so quick she caught the men's race - which had set off earlier.
The swimmer turned-cyclist, 34, now joins Baroness Grey-Thompson on 11 gold medals to become one of the most decorated British Paralympians in history, alongside swimmer Dave Roberts. The Manchester-based cyclist said: "I can't believe I pulled it off today. I'm just so chuffed, it was amazing."