The incident took place Sunday night when the 19-year-old pop star was performing one of his last songs, 'Believe'.

Justin Bieber
Justin Bieber

"A man ran on stage during 'Believe' and tried to grab Bieber and knocked the piano over," a source close to the singer told a website.
 
"He was a fan. Security detained the young man. All was fine and Bieber continued the show," he added.