The Hollywood star joined fiance Angelina Jolie and five of their six children for the premiere of 'Maleficent' recently. He was signing autographs when Sediuk jumped the barricade and grabbed Pitt.
The 50-year-old star said he managed to give the guy a crack on his head to extricate himself, reported People magazine
"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," Pitt told the magazine in a statement.
The actor got a restraining order against the former journalist, who has gained notoriety for disrupting major Hollywood events. Sediuk is now barred from such events.
"I don't mind an exhibitionist," Pitt said.
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," he said referring to Sediuk's stunt during the Cannes film festival.
The prankster had got into actress America Ferrera's dress while she was walking the red carpet at Cannes. He has also gatecrashed award shows like SAG and Grammys.