Rivalry games are a terrible way to judge a team.
I'm sure by the same token, Michigan fans weren't impressed with Ohio State's one-point win over their unranked team. That same unimpressive Ohio State team that struggled to put away inferior opponents is most likely headed to the National Championship game.
The same could be said about Oregon's one-point win against unranked Oregon State.
Rivalry games bring out the best in underdogs. Heck, a Top 20 USF team eeked out a win in overtime against a 4-8 UCF team back in 2008.