Demi Lovato takes a tumble on Madison Square Garden stage

Singer Demi Lovato fell flat on her back during a gig at New York City's iconic Madison Square Garden venue on Friday night (11Dec15).

The pop star was closing her 20-minute set at radio station Z100's iHeartRadio Jingle Ball concert with her hit Cool For The Summer, when she tripped over a mic stand, and crashed to the ground.

Demi pulled herself up and confidently raised a fist in the air in triumph as she laughed off the fall.

She later took to Twitter.com to assure her fans she was OK after the mishap, writing, "Don't you guys get it by now? Only cool kids fall on stage."

The accident-prone singer ironically had a wipeout during another radio station event, as she celebrated the release of Cool for the Summer in July (15) at a pool party in Los Angeles hosted by Kiis FM.

Demi slipped and fell onstage, and later tweeted, "Well… It's not a tour without busting a**!!! NOT cool for the summer."

It wasn't a great weekend for Demi - on Sunday she returned to Twitter to tell fans she was feeling unwell: "Sick in bed and bored," she wrote.