Victory for the Underdog
Rocky is the poster child for underdogs. He is a journeyman, an aspiring boxer whose drive has not typically matched his natural talent. He is a local boxer plucked from obscurity to face the internationally famous heavyweight champion of the world. Nobody is expecting Rocky to land a punch on Apollo Creed, let alone go the distance in the fight. He is the only boxer who has ever knocked Creed to the floor. He even wins the fight according to two out of three judges. He is the manifestation of the theme of victory for the underdog, and he achieves this victory primarily because he believes in himself. He is not scared of the challenge, he is not overwhelmed. He knows he can go the distance and believes in himself even when nobody else does.
Pride Goes Before a Fall
Apollo Creed is an incredibly talented and successful boxer; he is the heavyweight champion of the world and has never been knocked down. He has selected Rocky to fight him because he is local and because it is good publicity but he never considers him a challenger in the true sense of the word. Because of this, he is cocky and arrogant when he gets in the ring. He does not fight in the way that he would if he had more respect for the opponent. He does not protect or defend. He acts in a way that suggests he is already certain of victory. This arrogance is the main cause of his being knocked to the ground in the first round.
Hard Work Pays Off
Rocky has not worked particularly hard in his boxing career thus far - in fact his trainer has criticized him in the past for this because he considers that he is squandering his talent. When Rocky is given the title bout, he begins to work harder than he has ever done before, and utilizes what is around him to help him succeed. He practices jabbing on the animal carcasses hanging up in Paulie's meat packing factory. He becomes a dedicated, hard working athlete and eventually his hard work pays off.
