She might not have been the headline act but Cheryl Cole more than stole the show with a raunchy dance routine at the Capital FM Summertime Ball.

The pop star and her close friend and dancer Derek Hough got up very close and personal as they performed at the radio station's annual concert in London last night.

The pair have already set tongues wagging over their close friendship, with some suggesting they are romantically involved.

Flexible: Cheryl Cole holds on tight to Derek Hough as they perform a dance routine at the Capital FM Summertime Ball at Wembley Arena in London

And although it is not known if they are in fact dating, they did little to dispel any rumours about their relationship as they gyrated and danced closely together on stage.

Cheryl was one of many acts to perform at the gig, which took place at Wembley Stadium.

Arriving on stage just before 8.30pm and launched immediately into her number one single, Fight For This Love, as thousands of fans erupted into screams.

Just good friends? Cheryl and Derek hold on tight as they sink to the floor

Gyrating: Derek moves Cheryl sexily round his body as they dance to her hit single Parachute

Backed by a group of dancers who were all dressed in ripped army attire, she danced energetically to the song, which launched her solo career last October.

And she looked as though she was having the time of her life, all thoughts of her impending divorce to Chelsea footballer Ashley Cole firmly pushed to the back of her mind.

Fight for this love: Cheryl is accompanied by army-style dancers as she performed her biggest hit

And she showed off her lithe, petite frame in a pair of sexy pewter-coloured hot pants, a cropped green vest top and shiny gold boots.

She then slowed down the track before mixing it into a mash-up of Robin S's 1990 hit Show Me Love, before singing a couple more songs including her cover of Owl Cities' Fireflies.

You know the words! Cheryl invites the Wembley crowd to sing along

Her last track was Parachute which brought Hough onto the stage to dance with her, before they walked off stage hand-in-hand together with Cheryl shouting, 'Thank you very much Wembley, good night!.'

The headlining belonged to Rihanna, who jetted into the UK yesterday morning especially to perform.

Sporting her brand new bright red hairdo, she kicked off her set with Madhouse, the opening track from her album Rated R.

Good girl gone red: Rihanna sports her funky new red do as she performs as the gig's headlining act

Rude Girl: The singer treated the Wembley crowd to some of her biggest hits

She then launched into Rude Boy and Russian Roulette before ending her set with her biggest and most well-known song Umbrella.

Cheryl's set followed Dizzee Racal, who came on wearing an England shirt, and was joined by Florence Welch of Florence and the Machine for their version of You've Got The Love.

You Got The Love: Florence Welch and Dizzee Rascal cosy up for their duet

Dizzee came on after US teen sensation Justin Bieber who is starting to make a name for himself on these shores.

But he still had a helping hand from international superstars R&B singer Usher and Black Eyed Peas's star will.i.am, as the pair joined him on stage

Also performing at the gig were JLS, Alexandra Burke, Pixie Lott and Ellie Goulding.

Stars and stripes: US singers will.i.am, Usher and Justin Bieber delighted the fans with an impromptu performance

Here come the girls: Pixie Lott and Alexandra Burke delighted the Wembley crowd with their sets