You finally found that rare minfernal you've been camping for 4 weeks, and then your pet goes and one shots it. Don't flip your desk yet, there's a way to salvage this.
In my example you can see that I've killed the golden civet and then reset it. To do this, you just need to exit the game while at least one of the wild pets is still alive. Log back in and you'll see the battle pet you engaged is wandering around again. Of course you're gonna have to do it fast to beat others in the area.