On the April 2 episode of WWE RAW back in 2012, John Cena entered the ring and challenged then-rival The Rock to come out. John Cena said that he wanted to congratulate The Rock after The Rock defeated him at WrestleMania 28. As Cena waited, Brock Lesnar’s music started playing and 'The Beast' walked out. After eight years, Brock Lesnar entered the WWE ring and offered to shake hands with John Cena. As The Champ was reaching out to shake Brock Lesnar’s hand, The Beast delivered an F-5, thereby marking the beginning of a new feud.
A week later, Brock Lesnar entered the ring with General Manager John Laurinaitis. Laurinaitis proceeded to schedule a match between Brock Lesnar and John Cena for WW Extreme Rules. As Brock Lesnar was about to deliver a promo, John Cena’s music hit and The Champ walked out. They both stared at each other and after a few seconds, Cena slapped Lesnar. In reply, Brock Lesnar took John Cena down and began delivering a series of punches.
John Laurinaitis tried to stop the two superstars, but the two kept on fighting. The General Manager signalled the referees and the WWE superstars in the locker room to come out and stop the brutal brawl. At first, the WWE superstars failed to separate Brock Lesnar and John Cena as The Beast broke free and punched Cena, leaving him with the taste of blood in his mouth. Eventually, more superstars came in and attempted to separate the two. A bruised and bloodied Cena smirked and this time broke free and attacked The Beast. More superstars came and were able to separate the two for good.
This was an incredible segment as it was able to hype the PPV which was just two weeks away. John Cena ended up defeating Brock Lesnar in a critically acclaimed WWE Extreme Rules match. Dave Meltzer of the Wrestling Observer Newsletter gave 4.5 to the Cena vs Lesnar match out of 5. Wrestling critic James Caldwell described the main event match as "super-intense", saying that Brock Lesnar offered "physicality not seen in years". The match was also hailed as one of the top matches of 2012 by several websites, capping an exhilarating couple of weeks back in 2012.