#2 Steel Cage Match: Brock Lesnar vs. Vince McMahon (August 7, 2003)
After Paul Heyman turned on Brock Lesnar at Survivor Series 2002, Lesnar turned babyface. For a wrestler like Lesnar, who is the personification of a monster heel, he portrayed the "good guy" quite effectively. A heel turn, however was simply inevitable and came to fruition on the August 7th, 2003 episode of SmackDown.
Lesnar was supposed to battle Mr. McMahon in a steel cage with the WWE Champion Kurt Angle officiating the match. Lesnar and Angle had become friends after the latter's return in June of that year. However, the Olympic gold medalist dethroned his "friend" to win the WWE Championship at Vengeance 2003. This left a bad taste in the former champion's mouth.
In order to take this friendly rivalry to the next step, Lesnar ended up attacking Angle during the Steel Cage Match after initially pretending to be unconscious. This kicked off another chapter in their intense feud.