BRAD THROWN OUT OF SCREENING BY CONFUSED SECURITY GUARD!

Whoa!!! A TOTALLY confused security guard at screening of The Curious Case of Benjamin Button, last night in Westwood, actually tried to kick out Brad Pitt, the film's star!!!!

I guess it was the mustache that threw him off because as soon as Brad entered the theater, Charles (our photogs tell us is his name), charged at Pitt and attempted to force him back out the door! It seems he thought Brad was a paparazzo or a misguided fan.

Brad arrived late and was rushing into the theater and, as you can see in our exclusive pix, Charles really manhandles Brad as Brad resists the guard's force, pushing against him to attempt to continue into the theater.

X17 photographers on the scene say Brad was repeatedly yelling, "What are you doing, man?" He said, "Don't you know it's me?"

Security guard Charles didn't let up and finally Brad was so upset and annoyed he said, "I'm leaving!"

It was at that point that Charles finally realized the man he's been shoving and groping was Brad Pitt and he begged him to come back, saying, "No, stay; stay!"

Brad conceded and returned to the theater, stayed for about 15 minutes, and left!

Crazy!

So two things ... 1) Do you think Charles still has his job today? and
2) Couldn't Brad have just laughed this off instead of getting so mad? Can you say "ego"?!

You have GOT to check out the blow-by-blow in the gallery - CLICK HERE to see all the pix!