Biggest sports upset ever?

I’m still trying to wrap my head around what Appalachian State accomplished last weekend at the Big House in Ann Arbor.
While the Mountaineers are the two-time defending Division I-AA national champs, their 34-32 win at Michigan should stand alone as the most monumental upset in college football history to date. No ranked Division I team had lost to a team from a lower-tier classification until last weekend.
It might also deserve placement on a top-five list of the greatest upsets in sports history.
Here are my top five:
5. Citadel 10, Arkansas 3 in 1992. Arkansas coach Jack Crowe got fired the very next day.
4. Appalachian State 34, Michigan 32. The Mountaineers confirmed that team speed remains college football's great equalizer.
3. Chaminade over Virginia in 1982. The NAIA Silver Swords (great nickname) from Hawaii reenact the moment that David slung a rock into Goliath's eye. They took down a Ralph Sampson-led Virginia team in college basketball's greatest upset. This should have been the first clue that the 7-foot-4 Sampson might not pan out in the NBA.
2. The Miracle on Ice in 1980. The United States topples the Soviet juggernaut in ice hockey during the Winter Olympics despite having a roster filled with only a handful of viable NHL prospects.
1. Down goes Tyson. Buster Douglas, an absolute pug of a heavyweight with dubious technique and questionable resolve, makes Mike Tyson kiss the canvas in 1990 for the first time in his career.
I remember watching it unfold as a college student. A bunch of us ordered the fight on pay-per-view (why I don't know since Douglas was a 42-to-1 longshot) and I practically choked on my pizza slice when Buster downed Tyson with a five-punch combination.