Who would win in a fight a grizzly bear or a silverback gorilla?

After much discussion between myself and many of my fellow citizens we have come to the conclusion that the grizzy bear would quite simply destroy the silverback. Although the silverback is stronger and has apposeble thumbs the grizzly has razor sharp claws and theeth. If it's a matter of weight all my resources have said that they weigh about the same, anywhere between 500-700 LBS. Plus the grizzly is faster and quicker to react than the silverback.