It's the moment everyone's talking about from the MTV Movie Awards in Los Angeles: Comedian Sacha Baron Cohen, dressed as his flamboyant character Bruno, dropped down from the ceiling and landed right on top of Eminem, with his almost bare backside in Eminem's face.

Eminem seemed stunned, and his entourage swung into action to lift Cohen off him.

Cameras cut away to other shocked stars.  Cameron Diaz let out a nervous laugh and Zac Efron, who had just won the award for Best Male Performance, wasn't sure whether to get up and accept his award or not.

Eminem stormed off angrily.  The big question is, did Eminem know about the raunchy stunt in advance?  Or was he genuinely stunned?   

According to reports Eminem didn't show up for rehearsals, so he may not have known how he was literally going to be the butt of that joke.

Out on the red carpet Cohen stayed in character, dressed in a leopard print outfit, but gave no sign of the outrageous prank to come.  

INSIDE EDITION spotted teen queen Miley Cyrus, with her hair in a soft pony-tail.  And actress Sandra Bullock looked lovely in purple; the crowd went wild for her.

And Cohen's prank wasn't the only jaw-dropping moment of the night...Heroes star Hayden Panettiere made a foul-mouthed joke.

The stars of Twilight were the big winners of the night, taking home five awards, including Best Kiss.  When Robert Pattinson and Kristen Stewart took the stage to accept their award, they started to reenact their best kiss scene from Twilight, but it was a fake-out and they stopped at the last minute.

But it was Eminem's awkward encounter with Sacha Baron Cohen that everyone is talking about.