The reality star blew everyone else out of the water as she channelled her inner 80s chick and poured her catwalk worthy figure into this traffic-stopping scarlet number that boasted killer shoulder pads, a very slinky skirt and a plunging neckline.
Not her usual style at all but we are utterly obsessed! Oh, and er, HELLO cleavage.
Rosie owned the city streets as she strolled past the paparazzi, and thankfully, she managed to avoid an embarrassing wardrobe malfunction in the very low-cut dress in spite of the blowing wind!
The self confessed fashionista is never one to blend into the crowd and she contrasted her pillar-box red dress with a pair of magenta lace-up sandals instead of her failsafe Valentino nude courts.
Technically the look doesn't work on paper, but there's absolutely no doubt gorgeous Ms. Fortescue nailed it.
Rosie - who wore her honey-hued locks in effortless tousles - teamed her look with a boho-esque beaded shoulder bag and she kept her make-up fresh.
The star joined TOWIE's Chloe Sims, Chloe Lewis and Love Island's Cally Jane Beech at the bash but (shh!) she pipped them all to the post in terms of best dressed.
No change there, then!
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