Simply Red led singer Mick Hucknall was attacked on stage by a 20-year old man, in the middle of the concert.
According to The Sun, Mick was singing his last song, preparing to end the show, when a man suddenly lunged at him and attempted to punch him.
Mick, 45, ducked the hit and pushed the man into the orchestra pit.
Then, the singer decided his work was done there and announced: "Thank you, good night. That is the end of the show."
Hucknall's manager Ian Grenfell told the newspaper: "It was bizarre. What is so worrying is that we don't know what the man's intentions were. He was a Cuban American in his 20s and he stormed the stage and tried to attack Mick.
"Police say the man was stoned but what is unclear is why he took exception to Mick."