We've got the lowdown on where to buy their outfits, put together by top celeb stylist Frank Strachan (who also dresses The Saturdays, FYI!)
First of the girls to perform was Tamera Foster who, despite ending up in the bottom two, pulled off a silky smooth rendition of 'Wishing On A Star' by Rose Royce.
Nicole Scherzinger even described her performance as velvet with butter. Interesting!
The 16-year-old cheated the usual high street dress code by rocking scene-stealing trousers by 3.1 Phillip Lim. The trousers are no longer available to buy, but they were originally priced at an eye-watering £1345. Gulp.
She balanced out the cost of her dazzling numbers by pairing with a cheap-as-chips sequin cami, £22.99 from New Look. Phew!
Abi Alton earned tons of praise with her dreamy, pared-back version of Gloria Gaynor's 'I Will Survive'.
The singer-songwriter oozed glamour in a glimmering floor-length frock, which was a one-off vintage piece from Beyond Retro.
She added bold red lippy and a cute handmade floral headband, £20 from Beau xoxo.
Next up was Hannah Barrett, who pulled out all the stops as she sang 'Somebody Else's Guy' by Jocelyn Brown.
The young starlet turned heads with her outfit too, strutting her stuff in a glitzy custom-made fishtail dress from The Pretty Dress Company. Fancy!
Finally, Sam Bailey had us dancing on the tables with her performance of 'No More Tears (Enough Is Enough)', originally a duet by Barbra Streisand and Donna Summer.
The former prison officer set the stage alight in a black jumpsuit from Wallis (similar to this one, £50), customised with heaps of glitter by the X Factor style team.
Plus check out that super-size backcombed 'do - love!
Whose outfit do you prefer? Let us know by commenting below as the best comment across the site each week wins £50!