Susan Boyle’s surprise duet of I Know Him So Well with Peter Kay helps Comic Relief raise an astonishing £42m by 10pm

She’s long held Elaine Paige as her musical hero – and now Susan Boyle has become something of a hero herself for helping raise a staggering amount of money for Comic Relief by covering one of her songs.

The former Britain’s Got Talent star, 49, made a surprise appearance on tonight’s Red Nose Day extravaganza on BBC1 singing I Know Him So Well with Peter Kay, 37, in his Geraldine McQueen incarnation from his spoof Britain’s Got The Pop Factor…On Ice.

The duet was previously recorded by Elaine and Barbara Dickson from the musical Chess and was a Number One hit for four weeks in 1985.

Scroll down to see Elaine and Barbara’s original performance…

Game for a laugh: Susan Boyle and Peter Kay covered Elaine Paige and Barbara Dickson’s I Know Him So Well for Red Nose Day

On song: The pair’s hilarious performance boosted the Comic Relief coffers to a massive £42m by 10pm

Funny for money: Some of the bits of the spoof were spot on when it came to the original 1985 video of the Number One hit

Susan and Peter hilariously spoofed the original video of the song, which was written by Tim Rice along with Abba’s Benny Andersson and Björn Ulvaes.

Susan and Peter’s version meanwhile goes on sale on Monday to raise even more money for Comic Relief.

In a nod to the original video in all its Eighties glory, Susan has an enormous perm which keeps getting bigger, and at one point, the pair cook toast over an open fire.

In harmony: The pair actually turned out a sterling cover of the song, originally from the Tim Rice and Abba Eighties musical Chess

Hair raising: Susan’s normally modest curls kept increasing during the course of the spoof video

Red hot performance: Viewers appeared to adore the pair’s version of I Know Him So Well and donated in their droves

After the pair finished singing, they were seen emerging from the studio and walking down a corridor at BBC’s Television Centre, where Susan was heard saying to Peter: ‘Hurry up then, I want a cup of tea.’

Peter then replies: ‘Alright, keep your hair on’ – at which point they both take off wigs to reveal shiny bald heads underneath.

Wigging out: Susan and Peter were definitely being funny for money during their dazzling duet

Song take-off: Susan and Peter appeared to have a great laugh making the video for their version of I Know Him So Well

Moments later, presenters Fearne Cotton and Lenny Henry revealed that aftere just three hours on air, Susan and Peter’s performance had boosted the sum total to a whopping £42m.

The single and a DVD of their version of I Know Him So Well goes on sale on Monday