In 2002, Tito Ortiz was the undisputed baddest light heavyweight on the planet. Not only was he four defenses into his UFC title reign, but he also held a victory over then-PRIDE champion, Wanderlei Silva.
However, with former UFC Superfight champion Ken Shamrock leaving pro wrestling and returning to the world of MMA, a matchup between the two was immediately billed as the biggest fight in promotion's history.
This event came at a time where Zuffa was struggling, and this matchup single-handedly breathed new life into the organization. The buyrate came in at a whopping 150,000 buys, which doesn't sound like much by today's standards, but was three times bigger than other events at the time.
Without this fight, who knows if the UFC could have survived long enough to make it to their heyday.