Star of the show! Little Mix's Jesy Nelson upstages birthday girl Leigh-Anne Pinnock on X Factor night out

PUBLISHED: 08:33, 5 October 2012 | UPDATED: 10:06, 5 October 2012

She might have been hoping for a night in the spotlight but Little Mix's Leigh-Anne Pinnock had to take a backseat to her bandmate on her birthday night out in London on Thursday.

While the brunette singer looked elegant as she stepped out for her 21st birthday, Jesy Nelson stole the show, turning up in a knockout gown.

The brunette star, who's slimmed down since appearing on the X Factor last year, decided to show off the fruit of her labours as she joined bandmates at the Madison Restaurant.

Here come the girls: Perrie Edwards, Jesy Nelson, Leigh-Anne Pinnock and Jade Thirlwall get dolled up for a night on the town

Wearing a floor length, sparkly black dress, with a low-cut neckline and a thigh-high split, Jesy showed off her enviable curves.

Wearing her hair sleeked back in a ponytail and with large, smokey eyes, the talent show winner showed off her transformation.

Looking like a star, Jesy breezed out of the restaurant, although she had to deal with a male flasher as she headed to her car.

Classy lady: Jesy rocks the floor length gown which shows off her curves perfectly

Watch your step! Jesy keeps her eyes to the ground in her demure grey dress

Classy lady: Jesy rocks the floor length gown which shows off her curves perfectly

Perrie Edwards decided to go for a more demure look, wearing a vintage-style floor-length gown paired with a sophisticated clutch.

Elegant: The girls opt for old-school glamour as they hit London on Thursday night

Pulling out all the stops: Perrie and Jesy go all out for their bandmate's birthday night out

While Jade Thirwall opted for a loose-fitting sequenced black dress, the birthday girl went all out.

Starting the night in a floor-length, lace ball gown, Leigh-Anne was the picture of sophistication, but as the night progressed the popstar clearly wanted to show off a bit more of her slim figure and donned a see-through beaded dress, showing off her black bra.

Quick change: Leigh-Anne ditches her floor-length gown in favour of a floor-length number

The pop starlet decided to invite a host of X Factor contestants past and present to her party, perhaps with the intention of imparting some wisdom on the newbies.

X Factor wild card hopefuls Times Red showed up to the bash, as did Jake Quickenden, who didn't make it through to live shows.

Last year's wild card Amelia Lily is clearly still friends with the girl group and left the party hand-in-hand with another of last year's finalists, Craig Colton.

Reunion: Amelia Lily and Craig Colton show up to support friend Leigh-Anne

Wild Card: The boys from Times Red let their hair down before finding out if they've made it through to the live shows on Saturday

Lauren Goodger, never one to miss a party, showed up to Leigh-Anne's bash at the restaurant in St Pauls.

Wearing an all black outfit, the reality queen was clearly going for a sophisticated look, pairing skin-tight black trousers with a long-sleeved black top, cliched in at the waist.