How about this, throw three or four fast punches and then a devastating one. I personally feel that it is better to aim for speed in the initial few encounters in case he is a good counter fighter. Get him off balance or stun him with a quick shot, making sure you finish in a position from which you can throw one of you most powerful shots, and then unleash the fury. The one that works best for me is the jab/cross.
Sticks n stones'll break my bones, but if I land the first one, you're in trouble!