From what I understand, the dispute between the two wrestlers began in a tag match, which saw the Cena/Miz team lose the belt in less than 24hrs due to a rematch. In that match, Miz actually turns on his partner, Cena, and allows the other team to reclaim the tag team championship belt. After building tension between the fighters, they fought at the Wrestlemania 27 for the title of WWE Champion. Cena, who I always understood to be a face, received monstrous booing from the crowd as he entered. The match was back and forth for awhile, but appeared in favor of The Miz for the longest period of time as Cena constantly found himself severely weakened from a DDT by The Miz. Despite several near falls, Cena was able to push The Miz off of him and keep the match going. While performing the Attitude Adjustment, Cena took out The Miz as well as the referee. After this point, the match became a victim of foul play. With the referee down, Riley entered the ring and hit Cena with a briefcase. A minute later, The Miz missed Cena with the briefcase and struck Riley instead. Later, both men continued the brawl outside of the ring. John Cena got into a 4-point football stance and speared The Miz over a barricade. Ultimately, the match was considered a draw as neither man could get up from this powerful blow. As it stood, The Miz kept position of the WWE championship belt.
Even though the match had ended, The Rock's entrance music came on and he entered the ring. He spoke for a few minutes before demanding the match be restarted. Cena and Miz wrestled for a short period of time, then Cena walked into the Rock's Rock Bottom. The Miz pinned Cena and was declared the WWE champion once again. The show actually ended with The Rock performing the People's Elbow on Miz.
In my analysis, the match seemed slow and lacked the fluidity I expected. It was clear that Miz had the upper-hand on Cena, yet he used some clearly heel tactics such as the briefcase and assistance from Riley (Miz's VP of Corporate Communications). I was not thrilled by the body narrative of the match as there were clear signs of bad acting by both fighters. Nevertheless, I did thoroughly enjoy seeing The Rock make an appearance at the end of the match.