Brad Pitt has branded Vitalii Sediuk a "nutter."
The 50-year-old actor, who was attacked by the Ukrainian prankster at the Hollywood premiere of his fiancée Angelina Jolie's new movie, Maleficent, last week and subsequently secured a temporary restraining order against him, admitted he hit his assailant twice in the back of the head before Sediuk broke his designer sunglasses and was dragged away by security.
Speaking about the incident for the first time, the 12 Years A Slave star said: "I was at the end of the line signing autographs, when out the corner of my eye I saw someone stage-diving over the barrier at me. I took a step back; this guy had latched onto my lapels. I looked down and the nutter was trying to bury his face in my crotch, so I cracked him twice in the back of the head - not too hard - but enough to get his attention, because he did let go. I think he was then just grabbing for a hand hold because the guys were on him, and he reached up and caught my glasses."
Brad was horrified to hear Sediuk, who was placed on three years probation after he pled "no contest" to battery and unlawful activity charges stemming from the attack, also attempted to put his head under America Ferrera's dress at the Cannes International Film Festival last month.
He also told People.com: "I don't mind an exhibitionist, but if this guy keeps it up he's going to spoil it for the fans who have waited up all night for an autograph or a selfie, because it will make people more wary to approach a crowd.
"And he should know, if he tries to look up a woman's dress again, he's going to get stomped."
Sediuk, 25, has become known for pranking celebrities on the red carpet and previously accosted Bradley Cooper, Leonardo DiCaprio and Will Smith at red carpet events.
Along with his probation, he was also ordered to perform 20 days of community labour, undergo a year of psychological counselling and banned from attending all celebrity events in the future in court in Los Angeles on Friday.