Nicole, who looked looked stunning in a brown floor-length satin gown, tried to put the disappointment behind her as she headed to Mr Chow restaurant in London.
The former Pussycat Doll was joined by Sharon Osbourne, Louis Walsh, Gary Barlow and the show's host Dermot O' Leary.
Nicole, 35, looked effortlessly chic as she teamed her dress with gold pointed heels, and she kept her long sleek locks to one side.
The rest of the judges appeared to be in good spirits as they had seen their remaining contestants go through to the next week.
Despite impressing the judges over the weekend with her performance of Alexandra Burke's 2008 winner's single 'Hallelujah' during the X Factor's 10th anniversary celebrations, Hannah landed in the bottom two with Rough Copy.
The two acts had to battle for their place in the sing-off, but the results came as a shock, especially to Nicole, who told the studio audience: "I just can't believe this. These two acts should be in the finals.
"I am so disappointed and furious with the British public right now that my girl is in the bottom two for the third time."
After the sing-off, in which Hannah performed the Etta James classic 'I'd Rather Go Blind', the judges decided to save Rough Copy, leaving Hannah to be eliminated from the competition.
Taking to Twitter last night, Nicole posted a photo of herself with Hannah and said: "The last performance of Hannah said it all. Thank u to the believers! We didn't lose because we are #Li-ving & this is just the beginning for @HannahBMusic."
Got an iPad or iPhone? Reveal Mag is specially designed to fit!
Watch Hannah's sing off song below: