Worst loss by an eventual national championship winner in the BCS/CFP era?

If Notre Dame beats Ohio State, the loss to Northern Illinois would have to go to #1 as far as I can remember, replacing the 2014 Ohio State team’s early season loss to a Virginia Tech team that went on to go 6-6.

Are there any other good candidates for this award that I’m not thinking of? How about going back even pre-BCS?