The Emmerdale actor teamed up with close friend and comedian Baker for an impressive tap dance rendition of Fred Astaire favourite 'Puttin' On The Ritz', which topped tonight's viewers' vote and earned them an automatic place in the show's grand finale.
Clearly stunned by the results, Thornton gasped: "[I] genuinely don't believe that."
The show's guest judges Lee Mack, Jack Whitehall and Celebrity Juice host Keith Lemon were then asked to choose between the next two most popular acts, Fielding and his take on Kate Bush's 'Wuthering Heights' or legendary popstar Lulu and her hoodie-clad rendition of 'Crank That' by Soulja Boy.
Mack gave the first vote to Fielding, reasoning: "I find them both very alluring, but at the end of the day Noel did try and kiss me so I suppose I have to put Noel through."
Whitehall then opted to take, by his own admission, the coward's way out by voting for Lulu and burdening Lemon with the deciding vote.
After his appeal for an X Factor-style deadlock was turned down, Lemon stated: "I like Lulu cos she's right nice and that, but Noel Fielding also looks attractive. I've never fancied a man before."
Under pressure from hosts Steve Jones and Alex Jones, as well as his fellow judges, Lemon finally snapped and shouted out Fielding's name.
Following his win, Fielding declared himself to be "flabbergasted" and "excited", while Lulu brushed off her defeat by saying: "It was fun, but remember what it's all about, it's all about the charity."
The other failed acts in tonight's show were GMTV star Penny Smith, who became an air hostess for her send-up of 'Toxic' by Britney Spears, Jarred Christmas and his leotard-heavy rendition of 'Hung Up' by Madonna and Andi Osho with her take on Michael Jackson's 'Bad'.
The first two places in the Let's Dance final were won by Russell Kane and Katie Price last week.
The Let's Dance For Comic Relief final will be shown on March 12.