Animal fighting strategies

Google isn't working for me with this, so I'm hoping someone here can help.

I am trying to find an example of an animal that might pretend to be hurt/weak/dead when confronted with an aggressor or in the middle of a fight, so that the aggressor would come closer with its guard down and the first animal could surprise it with a sudden attack. I would think this would be most likely to happen between members of the same species. Does anyone know of a type of animal that will use this sort of behavior?

Thanks in advance!

(Note: I know there are many species that will play dead to get a predator to leave them alone, or play hurt to lead a predator away from young, but I'm specifically looking for one that would use it to get the upper hand in a fight/attack.)

Possibly this doesn't actually happen; I thought I'd remembered hearing about this sort of behavior but could be wrong. I'm not talking death matches or trying to kill, just if two animals were fighting over food/territory/mates one might do this to get the upper hand.

e.g., Cats will do this when they're play-fighting--one may roll over on its back to play vulnerable, and then lunge when its play-mate "attacks". I was hoping there might be a species that does something along that line in a serious fight.

(In the context of the story, it would be two animals; would not be something the animal would do with a person.)

janwyl, thank you, that example is actually perfect!