Jamie said the final half-mile "was the most euphoric thing I've ever had" and added: "That was a wild ride everyone.
"That was intense at times. That was emotional. I've never cried more in my life."
It was one of a number of high-profile fundraisers as Red Nose Day celebrated Comic Relief's 40th birthday with another huge night of comedy and entertainment.
The three-hour extravaganza on BBC One kicked off with a homage to the 1980s, with Kajagoogoo's Limahl, Carol Decker of T'Pau and Roachford taking to the stage to perform their hits. Noughties girl band Sugarbabes also performed.
Delirious
Actor and comedian Sir Lenny Henry and Love Actually screenwriter Richard Curtis co-founded the charity in 1985.
In a pre-recorded video Sir Lenny said: "I can't believe Comic Relief is turning the big 4-0. In some ways, it feels like 19...