The blonde singer added plenty of lashes and a bold red pout for her performance on day one of the two-day festival on Saturday, 31 August.
As well as a high-octane show from Jessie, festival goers were treated to performances by the likes of The Saturdays, The Wanted, JLS, McFly, Ne-Yo and Amelia Lily at the musical extravaganza, in aid of The Prince's Trust.
Jessie, who shaved her head for charity last year, is showing no signs of missing her longer locks, and wore her blonde crop in a spiked 'do.
The 25 year-old looked remarkably perky despite a round trip to the other side of the world just last week.
Jessie has just returned from Sydney, where she treated fans to a knockout performance for Australian TV.
Watch Jessie's video for 'Wild' below: