A hard right hand had Griffin stumbling toward the ground, and Rua went on the attack, knocking Griffin down and jumping on top of him. From there Rua rained down punches from the top, and the dazed Griffin could do nothing but flail in his attempts to block Rua's punches. As Rua began to land hammer fists Griffin couldn't do anything, and the referee eventually stepped in to stop it after it was clear Griffin was out of it.
Although Rua was brutalized by Jon Jones at UFC 128 in March, no one should take that result as evidence that Rua is done: He improved his professional record to 20-5 and showed against Griffin that he has plenty of fight left in him.
Griffin, who fell to 18-7, will always be one of the UFC's most popular fighters, and he'll have a lot more big fights ahead of him. But this bout showed that while Rua is among the truly elite fighters in the light heavyweight division, Griffin is not.