Ed McKeever powered to victory in the men's 200m kayak to win Britain's 26th gold of the Olympics.
The 28-year-old dominated the K1 single final, with Spaniard Saul Craviotto Rivero taking silver and Canada's Mark de Jonge bronze.
"He blew the field away from the start, leaving everyone else trying to catch him. A fantastic performance. That core strength that drives the blades and the focus this man has is incredible and he hasn't been fazed by anything."
McKeever crossed the line in 36.246 seconds to win Britain's second ever Olympic canoe sprint gold medal after Tim Brabants triumphed in 2008.
McKeever adds Olympic gold to his 2010 World and European titles.
"I'm so happy," he said. "I feel relief. It sounds stupid but it's not elation, more relief, and I'm so happy to do it front of a home crowd.
"I was like a kid at Christmas this morning, waiting to open his presents. I get to open those presents soon."
After a barren week for Britain in the canoe sprint events, McKeever raised hopes of a medal when he set an Olympic record in the heats, as gold medal favourite Piotr Siemionowski crashed out.
McKeever relieved to deliver gold
McKeever slipped to the third fastest time overall in the semi-finals, behind de Jong and Craviotto Rivero, although only 0.024 seconds separated the trio.
But on finals day, McKeever, who is training to become an accountant, fed off the energy from a cheering 30,000 capacity crowd.
A blistering start gave him an early lead and he was soon into a smooth paddling rhythm as he kept up the ruthless pace to hold off the chasing pack and take gold.
"A hard wind made the race a bit longer," he said. "I wanted to focus on the first three strokes. I wanted to nail them and hopefully the rest sorted itself out, which it did."