1108, 447, and 492 are the only 8th seed to ever beat the 1st seed in Atlanta before the advent of the serpentine draft (Galileo, 2005). I watched it happen, but I don't remember any particularly big gameplay moments (but then again, I was pretty short and sitting in MOE territory while they were playing
), just afterwards being like, "that was weird" and looking it up on CD to find I'd witnessed FIRST history.
At regionals, IMHO there is a much greater potential for bad picks by unprepared top seeds and always has been. While some of these wins may be remarkable, I'd venture a decent portion of them are based in partly on the poor picks of others.