Jessie J made a big impression at the Capital FM Summertime Ball, shrugging off illness to perform in a see-through dress.
The Voice coach joined Justin Timberlake, Robbie Williams, Taylor Swift, Will.i.am, The Saturdays, Labrinth and Olly Murs on the star-stuffed line-up to wow the 80,000-strong crowd at Wembley Stadium.
Jessie tweeted before going on stage: "Time to rest before glam time! I refuse to be sick! No no no sickness! You ain't gonna win! Muhahahaha!"
She hid any illness as she jumped around on stage in a meshed maxi-dress with nude-coloured underwear underneath, and danced wih B.o.B to her song Price Tag.
Timberlake wowed the crowd with an acoustic medley of classic tunes and some of his own most popular tracks. He sang Ain't No Sunshine When She's Gone - made popular by Marvin Gaye - and the Elvis Presley hit Heartbreak Hotel, as well as Cry Me A River and What Goes Around from his own back catalogue.
Taylor, wearing a white top, black shorts and a black hat, was surrounded by dancers in colourful outfits as she opened her set with the single 22.
She invited surprise guest Ed Sheeran to join her on the stage, describing him as "one of my absolute best friends in the world" before they performed their duet Everything Has Changed.
Backstage insiders revealed Taylor was surrounded by an enormous entourage at all times, and had to be given the biggest dressing room to fit them all in.
Robbie Williams closed the show, strutting onto the stage wearing a bright red blazer and black trousers, before launching into his 1998 hit Let Me Entertain You.
Robbie, who was accompanied by musicians playing brass instruments, also performed Rock DJ and his latest single Be A Boy as he brought the curtain down on the spectacular show.