Irwin and other 5 Seconds of Summer members got a little bit over-excited while headlining the stage in Pennsylvania's Hershey Park over the weekend, reported Aceshowbiz.
"Chipped a tooth tonight, I went hard out lol... Thank you Hershey park, it was a night I'll remember forever," he tweeted.
The band is currently working on their second album, "Sounds Good Feels Good" which is a follow-up to their 2014 self-titled set.
It is due for October 23 release.