As stunned spectators at the Atlantic stadium watched, Thatcher ran to first place in 32 minutes and 20.27 seconds. He took Britain's 44th gold medal in the games, as part of a Paralympic team that has already outshone the able-bodied athletes who competed there earlier this summer.
His achievement was praised by Brendan Foster, the former 10,000 metres record holder, who said: "To win a record in that time at the Paralympics is unbelievable, especially under those circumstances. For an able-bodied athlete 50 seconds would be staggering, and it must be a performance of that magnitude, on a par with Michael Johnson's performance."
Thatcher, 30, a physiotherapist from Harlow in Essex, has spent the last year flying from London to Japan, for sessions with elite marathon runners who are experts in the psychology of long-distance running. He fractured his shin two weeks ago under the strain of the rigorous training.
He said: "When you've been training for something for four years it's just an amazing feeling to win. It took a long time to sink in, that I'd done it, and that I'd broken the record in that time, it was unreal, and it was only when I had breakfast today that it began to feel real."
Thatcher added: "I didn't feel the leg at all while I was running. It was only afterwards, and then it was really painful. It's a runners' thing. My coaches in Japan have helped me with the mental preparation for this kind of race, which gave me the strength to keep going. I've also never had such an emotive or supportive crowd."
Despite the pain in his leg, Thatcher is also determined to run in the 5,000 metres tomorrow and emulate his hero, Emil Zatopek, the Czech athlete who won gold medals in both races at the Helsinki Olympics in 1952.
His shin was put under extra pressure when he agreed to run in Britain's 4x100 relay heat, just one hour before the 10,000 metres, to allow a team mate to recover from a hamstring injury.
For Britain, the Paralympics have increasingly brought more glory than the traditional games, where British athletes won only one gold medal this year. The Paralympic team is set to equal its performance at the last games in Barcelona, where it came third on the medal table, out of 127 competing countries.
According to Thatcher, it is the strong team spirit among the British athletes that has brought them such an impressive haul of medals. He said: "It's a brilliant spirit, and it's contagious. Winning is catching out here."