Katt Williams attends Rick Ross' 40th Birthday Celebration on January 28, 2016 in Fayetteville, Georgia.

Katt Williams attends Rick Ross’ 40th Birthday Celebration on January 28, 2016 in Fayetteville, Georgia.

*The erratic behavior of Katt Williams continues.

On Sunday, he was at a rap concert in Philadelphia when he suddenly hurled himself at some dude, sucker punching him before being beaten down, according to TMZ, which posted video of the incident.

It all went down Sunday night at the Trocadero Theatre … where Beanie Sigel, Jahlil Beats, Jadakiss and a few other rappers were performing.

Williams was all over the place … freestyling onstage, randomly doing pushups and standing around in a fight stance for no reason.

Williams suddenly ran full speed at someone onstage and clocked them. The dude he decked had a loyal entourage … which beat Williams down.

No one was arrested.

This latest incident follows his arrest in Georgia last week for allegedly punching a store clerk, which came one day after he allegedly held five women at gunpoint. A few days later he got into a fight on the streets of Los Angeles.