Tyler Perry had to take a break from filming new action thriller Alex Cross after landing a sickening blow on co-star Matthew Fox during a fight scene.

The actor/director trained with Krav Maga specialists to perfect his fight sequences in the film, but when it came to unleashing his martial arts moves, he almost knocked the Lost star out.

He tells Wenn, "I kept feeling within myself that he (Fox) was too close. I wouldn't commit all the way to the turn and I was afraid to completely let go because this Krav Maga training I took is really amazing. I had major issues because I didn't want to hurt him.

"But (director) Rob Cohen kept pushing me and pushing me, and finally I just let go. My elbow came too close and I hit him in the temple. Matthew spun around and we're on the catwalk of this scaffolding and I grabbed him because I thought he was going over.

"He was a good sport about it because he didn't turn around to kick me. I had to leave the set after that because that was it for me; I didn't want to be that committed!"

And Fox admits his co-star spent the next few days apologising for smacking him around the head: "You do those fight sequences and they're really drawn out and you're exhausted, so every now and then somebody makes a mistake and you misjudge and somebody gets hit.

"Tyler caught me with an elbow in the face about midnight on the scaffolding when we were doing that stuff. He was so unbelievably horrified that he did it that he called me every day just apologising. I tried to let him off the hook saying, 'It's no problem man'. I didn't get seriously hurt."

But it was a different story for a stuntman on the film - he reprimanded Perry after the star pushed his son out of the way during a fight scene in a restaurant.

The actor recalls, "I decked this waiter in the scene. Rob says, 'Go on, man, you're gonna try and save your wife. Knock him out of the way!' So I run and I knock the guy out of the way.

"After the scene, everyone is quiet and the stunt guy comes over to me and says, 'Hey man, that's my son. You can't hit him like that!'"