Comedy role hit for Blair.
A DVD featuring the performance racked up the fastest sales orders on internet retailers Amazon's website ahead of its release next month.
And the DVD leapt to the No1 spot following a rush by buyers after it was shown on Red Nose Day last Friday.
In the sketch with the PM, stroppy teenager Lauren takes a work experience placement at Downing Street, where she turns her lack of charmon Blair.
But he has the last laugh as he utters her catchphrase "Am I bovvered?", much to the sulky schoolgirl's dismay.
The DVD also features Doctor Who star David Tennant, Lenny Henry and Noel Edmonds.
The PM's acting ability has had a warmer reception than Margaret Thatcher's disastrously wooden 1984 sketch for the comedy Yes, Minister.
Amazon spokesman Ben Howes said: "Tony Blair's sketch was actually very funny and he obviously has a talent for comic acting.
"I think that, in terms of the night as a whole, Comic Relief pulled out all the stops this year, which is why the DVD is doing so well."
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