The gorgeous judge slipped out of the slinky dress she'd been wearing on screen and into a sexy black jumpsuit with lace detailing to dine at the capital's C Restaurant on Sunday evening (8 December).
Flawless. As always.
Nicole, 35, was mentor to the girls category on this year's show but unfortunately lost her last remaining act last week when Tamera Foster was voted off, narrowly missing a place in the semi-final.
But having no acts left also meant this weekend she could enjoy the live shows without the added pressure of worrying about her own contestants. Of course, it wasn't an entirely easy weekend for Nic as she still had to vote off another act on the Sunday results show.
Gary Barlow's group Rough Copy fell into the bottom two alongside Louis Walsh's act Luke Friend and both had to sing for survival and a place in next week's finale alongside Sam Bailey and Nicholas McDonald.
Nicole backed Gary in saving Rough Copy but when Sharon Osbourne brought it to deadlock the public vote sent home the trio. After the show Nicole tweeted: "Going to miss these boys @RoughCopyUK in the @TheXFactor finals next wk. God bless them!"
Former Pussycat Doll Nicole wasn't the only star backing Rough Copy for success as the boys received an outpouring of support from famous fans via Twitter including JLS' Marvin Humes, Tinchy Stryder and Wretch 32.
Marvin - who shot to fame on X Factor - tweeted: "Big congrats to @RoughCopyUK you did it fellas and smashed it out the park! I'll be one of the first to buy your album! Good luck fellas."
The X Factor final starts Saturday, 14 December on ITV.