Taylor Swift, Nicki Minaj and One Direction thrill fans at iHeartRadio festival

Taylor Swift, Nicki Minaj, One Direction, Ariana Grande, Coldplay and Iggy Azalea were among the high-profile stars who took to the stage in Las Vegas over the weekend (19-21Sep14) for the iHeartRadio Music Festival.

Some of the biggest names in the music industry graced the stage in Sin City for the two-day event, which kicked off on Friday (19Sep14) with acts including Swift, Minaj, Grande and Coldplay.

Coldplay's set was overshadowed by the appearance of actress Jennifer Lawrence at the gig, fueling rumors she is dating frontman Chris Martin, while other acts included pregnant singer Alicia Keys, who made a surprise turn on stage to perform her new single We Are Here.

Black Eyed Peas star will.i.am also made a surprise appearance onstage with DJ Steve Aoki.

Usher rounded out Friday night by bringing out Chris Brown for a rendition of his single New Flame, and the Yeah! star baffled the crowd by setting his sneakers on fire. The flaming shoes were dealt with by a stagehand who doused them with a fire extinguisher.

Iggy Azalea, 5 Seconds of Summer, Magic!, One Direction, Lorde and Paramore all took to the stage on Saturday (20Sep14) to close the festival. Calvin Harris brought out British pop star John Newman during his Saturday set, while Ed Sheeran performed with rapper Macklemore.