Andy and Jamie Murray in Some Mothers Do 'Ave 'Em Sport Relief sketch
Tennis siblings Andy and Jamie Murray have teamed up with Michael Crawford for the Some Mothers Do 'Ave 'Em Sport Relief sketch.
In their cameo appearance, the two Grand Slam winners watch on while Crawford's hapless character Frank Spencer whizzes around London's VeloPark track on his roller-skates.
England coach Roy Hodgson and Arsenal manager Arsene Wenger also feature in the sketch as themselves.
The sporting quartet join the previously announced Sir Bradley Wiggins, Jenson Button, Sir Paul McCartney and David Walliams to complete the special cameo line-up.
Michele Dotrice has returned as Frank's long-suffering wife Betty, and Quantum of Solace's Gemma Arterton will be seen as their daughter Jessica.
Crawford, 74, last wore his famous beret to play disaster-prone Frank in a 1978 Christmas special of the popular sitcom.
The celebrity-laden segments are part of a star-studded weekend of fundraising for Sport Relief on the BBC.
The live extravaganza will be broadcast from London's Queen Elizabeth Olympic Park on March 18, and presented by top names in sport and entertainment.
Walliams will also present, with Claudia Winkleman, John Bishop, Alesha Dixon, Gary Lineker, Davina McCall and Greg James among the names taking on hosting duties.
Britain's Got Talent judge Walliams, who has a long association with Sport Relief, revived Little Britain character Emily Howard for a Sport Relief sketch with former England footballer Peter Crouch.
Alongside Stoke City's Crouch, the 44-year-old will be joined by comedian Micky Flanagan.
The night will also see Idris Elba star as Luther in a one-off sketch which will reunite him with Ruth Wilson.
The acclaimed actor will don his character's famous overcoat to uncover a serious case of hilarity with Wilson, who plays nemesis Alice Morgan in the BBC One crime drama.
As super sleuth Detective Chief Inspector John Luther, Elba will also be joined by Sir Lenny Henry, former England footballers Rio Ferdinand and Ian Wright, boxer David Haye, Olympians Denise Lewis and Louis Smith and actress Cecilia Noble.
Comedian Jack Whitehall will be seen enlisting Gareth Bale in a bid for English football glory at the Euros this summer.
Viewers will be treated to live events from Lee Valley VeloPark and London Aquatics Centre throughout the night.
Sir Steve Redgrave and Andrew "Freddie" Flintoff will captain two teams of celebrities in a return of the Clash Of The Titans competition, hosted by the BBC's Dan Walker and Ore Oduba.
Take Me Out's Paddy McGuinness and McFly's Harry Judd will go head-to-head in a wrestling spectacular and Russell Kane and Will Young put on nose pegs for synchronised swimming routines.
Former cricketers Flintoff and Darren Gough will also have their twirling batons at the ready for rhythmic gymnastics.
Comedian Jo Brand and Greg James will relive their outstanding fundraising challenges, while Eddie Izzard nears the climax of his epic 27-day Marathon Man endeavour in South Africa.
Brit Awards winner James Bay will perform the official Sport Relief 2016 single and there is also live music from Birdy.
Powerful films will remind viewers why Sport Relief is appealing for money, as the charity endeavours to change lives both here in the UK and around the world.
:: Sport Relief is broadcast on March 18 from 7pm on BBC One.
:: For more information and to donate, go to sportrelief.com.