Matt Serra was a fat lightweight. He was a UFC washout. He wasn't some unknown with the chance of a life tiem. He was incredibly, painfully known, everyone knew he didn't have a chance, and that made him winning all the more incredible.
In a vacuum, Shamrock/Horn might not seem like much, certainly compared to fights of today it pales, but at the time it was almost an aberration, in much the same way that UFC 17 was. It was the start of a new wave. So, it is fitting that we look at the main event of the card that night, at least for the fans in the arena, and see what the future of MMA, or more appropriately NHB, could be in 1998.
LeBell-Savage is ur-MMA, the very beginning of the concept that would, several decades later, crystallize as MMA. Everything before it, and some things after it, are proto-MMA, part of the process, but not quite the genuine article.