While completing our MMA Awards post for 2025, I started to wonder what the biggest upsets of all-time were. We have four different upset awards, each using different rules and/or rating systems.
In this post, we will consider all pro fights with only one exception — the winner must have a pro loss prior to the fight date. I will however, post some notable fights that would’ve otherwise qualified.
To determine the order, we will use ratings from the Elo and Glicko systems, total the pre-fight ratings for each fighter, then order by the difference.
Prepare to read about some fighters you’ve probably never heard of…
Upsets
#5 – (1497pts) [3-4-0] Shana Dobson W(TKO) [9-1-0] Mariya Agapova
UFC on ESPN 15 (September 22, 2020)
I’m a little surprised that a UFC fight made the cut, especially in the women’s list. As far as the outcome, ESPN referred to it as a “historic upset”. From what I recall, Agapova came into the UFC with a ton of hype and a pretty nice 9-1 record. Dobson, at around +850, derailed the hype train.
