It was heavily promoted second fight between Georges St. Pierre and BJ Penn. Many people expected pretty equal fight due to caliber of both fighters. Interestingly, there was a poll running right before the fight and with 10,000 votes there was only slight advantage give to Georges St. Pierre 51% vs 40% for BJ Penn.
First round started with both fighters sizing each other. Georges St. Pierre tried to bring BJ Penn down to the ground but could not do that after several attempts. It was clear and Georges St. Pierre was trying to bring fight down to the ground.
Second round was more intense with Georges St. Pierre making several successful attempts to being BJ Penn down. He was able to do so and BJ Penn took a beating. It was clear that Georges St. Pierre strength and superior conditioning started to pay off.
Third period was almost replica of the second with BJ Penn being on his back and Georges St. Pierre in half guard on top of him and gradually punching and grinding BJ Penn.
Fourth round was even more unequal with BJ Penn running out of gas and Georges St. Pierre getting more aggressive trying to finish this round with the knock down. Georges St. Pierre has few good swags at BJ Penn face cutting him under his right eye. At the end of the fourth round doctor examined BJ Penn and his brother called it off due to extensive damage.