Hanging out with Cara Delevingne hasn’t taken the pop princess sparkle out of Selena Gomez just yet.

Former Disney child star Selena may have arrived at Wednesday night’s Leonardo Dicaprio Foundation Launch in a daring side-split slinky gown, but she later changed into a pretty black prom dress.

The 22-year-old raven-haired beauty made a quick change at the exclusive St Tropez auction, managing to pull off two totally different looks in one A-list filled evening.

After spending the day sunning herself in the French Riviera with new gal pal Cara Delevingne, Selena Gomez looked flawless stepping off a boat in an asymmetric Grecian dress on her way to the Domain Bertraud Belieu vineyard.

The gold floor-skimmer was a dress of two halves, as a slinky satin-sheen layer cut away into a sultry studded slip dress, which revealed the singer’s toned legs.

With her hair pinned back into a refined, low chignon, the svelte star struggled to conceal her modesty in the thigh high slit as she strode along the coast in coordinating gold stilettos.

Later though, the star slipped into something a little more comfortable, rocking a full-skirted fairytale dress that cut off at the knee.

A fitted bodice that highlighted Selena’s tiny waist broke into a black tutu-style skirt, which she again coordinated with her shoes.

To dress up the earlier evening’s elegant up-do, the star accessorised with a veiled headband.

The exclusive evening event, the first of its kind, raised over $25million for rare wilderness area, with an auction that began with the sale of a Harley-Davidson motorcycle, laid on by host Leonardo DiCaprio, with Martin Scorsese and Robert De Niro.

Stars including Daisy Lowe, Petra Neomcova and Marion Cotillard enjoyed entertainment from U2 frontman Bono, as well as Robin Thicke.