The footage begins in the middle of the verbal altercation outside an after-party for a music award show in Toronto -- moments after Hilton claims Will went after him like a "heat-seeking missile" and unleashed a verbal tirade at him.
With a crowd surrounding Perez, Will and Will's manager, Polo -- the guys argue back and forth for about a minute, until Perez tells Will, "you're not a f**king artist ... you're a f**king f*ggot."
The scene suddenly turns chaotic -- and in the mess someone punches Perez in the face.
On a video blog on his website, Hilton claims Will's manager hit him "two or three times."
Will also posted a video blog saying he never hit anyone.