Dude, it's a Pokemon battle, not a duel to the death.
Make sure you're using Pokemon with at least natures that don't suck (Modest on Snorlax, for example, sucks) and make sure your Pokes are EV trained and have halfway decent IVs, and I bet you'll school him.
Play a few practice battles on Pokemon Online or whatever simulator you want to use before training your team on your cart/save file.