Def Leppard's one-armed drummer Rick Allen suffered a head injury after cops say he was violently assaulted by a teenager in an apparent sneak attack at a South Florida hotel.

According to an arrest report, obtained by TMZ, Allen was puffing on a cigarette as the suspect was lying in wait behind a pole outside the Four Seasons Hotel in Fort Lauderdale Beach.

Rick Allen, who sadly lost his arm in a car accident back in 1984, was outside the Four Seasons in the valet area for a smoke. That’s when a very strange and scary encounter happened.

Allen was in South Florida to perform a show at the Seminole Hard Rock Hotel and Casino over the weekend.The show, this past Sunday, had Def Leppard co-headlining with Mötley Crüe.Allen, 59, was staying at the Four Seasons on Fort Lauderdale Beach.

Police say the teen suspect, Max Hartley, then ran toward Allen at full speed, striking him and knocking him backward and slamming his head on the ground.The report says a woman came out of the hotel to try to help Allen, but Hartley also knocked her to the ground.

Hartley fled to another hotel nearby, but was ultimately arrested after he allegedly damaged numerous cars in a parking garage. The 19-year-old was booked for elder abuse, battery and criminal mischief. He was later released after posting bail.

According to the report, “While she is on the ground, the defendant continues to batter her by striking her. [She] attempts to escape by running into the hotel. The defendant then grabs [her] by her hair and drags her out of the lobby and back onto the sidewalk before fleeing the area.”

Def Leppard and their 59-year-old drummer were in South FL to co-headline a Sunday concert with Mötley Crüe at the Seminole Hard Rock Hotel and Casino.