The Outnumbered and Tracy Beaker stars won the first spot after topping the public vote with their homage to the musical Bugsy Malone.
Djalili was then sent into the final by judges Tim Minchin, Katy Brand and Ed Byrne, who favoured his musical interpretation of the London riots over Olly Murs and Scott Mills's performance to LMFAO's 'Party Rock Anthem', featuring a guest appearance from David Hasselhoff.
Also competing tonight were Kirsten O'Brien, who unleashed an energetic routine to Van Halen's 'Jump' despite only giving birth ten weeks ago, and comedian Arabella Weir, who channelled Kylie Minogue for a performance of 'Can't Get You Out Of My Head'.
Eddie 'The Eagle' Edwards, Miles Jupp, Terry Alderton and the team of Laurie Brett and Tameka Empson previously won a place in the March 17 final.
Let's Dance for Sport Relief returns next Saturday (March 10) at 7.10pm on BBC One.