The Tears songstress looked all kinds of fierce as she ditched the glamorous frocks and gasp-inducing PVC numbers (Lauren Pope, we're looking at you) and sported a pair of high-waisted cropped jeans that boasted a frayed flare and acid wash detail along the thighs.
Louisa - who was met by hundreds of fans outside the city venue - took things back to basics and flung on a simple navy tee, but even though the majority of her look was pretty laid-back, she couldn't resist slipping into a pair of sky-high metallic platforms which gave her ensemble a dose of 70s cool.
Totally catwalk worthy, right?
Just last month, Louisa took her beautiful blonde locks a mermaid-inspired shade of lilac sending fans and beauty-obsessives into a bit of a meltdown, but she went right back to her roots in time for the star studded affair.
If anyone can pull off a dishevelled wave and centre part combo, it's our Louisa.
Also making a splash on the day were singers Ellie Goulding, Ella Eyre and Alesha Dixon, but it's safe to say Lou hogged all of the limelight - gah, we love her!
Follow us on Twitter @RevealMag for all your celeb, fashion and beauty news!
Fancy winning some GREAT prizes? Check out Reveal Competitions here!