Consensus Rankings:   Official  |  Member Designed  |  This Ranking Updated 12 years, 10 months ago  |  All By Steven_Abootman

1. 1

   

   Emelianenko vs. Werdum

   Fabrício Werdum | Submission | Round 1

   2010 | Strikeforce

   Undefeated 32-0 Fedor, goes in against gigantic underdog in Fabricio Werdum in a match up that had no relevance at the time. Werdum wins in 69 seconds. Biggest upset ever
   

2. 2

   

   Serra vs. St-Pierre I

   Matt Serra | KO/TKO | Round 1

   2007 | UFC 69

   GSP had just won the belt, and in his first title defense he faced TUF 4 winner, Matt Serra; a gigantic underdog. Serra TKO'd GSP in the first round in one of the strangest happenings.
   

3. 3

   

   Gonzaga vs. Filipović

   Gabriel Gonzaga | KO/TKO | Round 1

   2007 | UFC 70

   Cro Cop entered the UFC after a marvelous Pride career, being warmed up for a title fight. He faces Gonzaga on live TV for hype and gets KO'd by his signature move; Left Head Kick
   

4. 4

   

   Penn vs. Edgar I

   Frankie Edgar | Decision

   2010 | UFC 112

   At the time Penn was considered a P4P top 5, best 155'er in the world and seemingly unstoppable with a clear division. Edgar comes in from nowhere and outwrestles Penn.
   

5. 5

   

   Griffin vs. Rua I

   Forrest Griffin | Submission | Round 3

   2007 | UFC 76

   Shogun enters the UFC as a huge Pride superstar. He was expected to beat Forrest and get a title shot. Instead Forrest, who's not even a submission specialist, submits him in the 3rd.
   

6. 6

   

   Couture vs. Sylvia

   Randy Couture | Decision

   2007 | UFC 68

   Everyone was growing tired of having Tim Sylvia as the champion yet nobody could seem to beat him. 47 year old Couture comes out of retirement and captures the belt.
   

7. 7

   

   Chonan vs. Silva

   Ryo Chonan | Submission | Round 3

   2004 | Pride Shockwave 2004

   Throughout the fight Anderson was dominating Chonan on the feet. Late in the fight, Chonan throws a rare Flying Scissor Heel Hook out of nowhere and submits him.
   

8. 8

   

   Liddell vs. Evans

   Rashad Evans | KO/TKO | Round 2

   2008 | UFC 88

   Liddell was very much expected to beat Rashad in this outing. Instead Rashad dances around, frustrates Liddell and knocks him out in the first. Very strange.
   

9. 9

   

   Lauzon vs. Pulver

   Joe Lauzon | KO/TKO | Round 1

   2006 | UFC 63

   The irony of the situation is that Lauzon was later on the season that Pulver coached on, after he had knocked him out in the first round.
   

10. 10

    

    Slice vs. Petruzelli

    Seth Petruzelli | KO/TKO | Round 1

    2008 | EliteXC

    The fight that folded an organization. Seth Petruzelli took the fight on less than a days notice, and finished cash-cow Kimbo Slice in the first round.
    

11+

11. 11

    

    Brown vs. Faber I

    Mike Brown | KO/TKO | Round 1  |  WEC 36

    Urijah Faber is widely considered the FW GOAT. He was on a dominant win streak the likes of which the WEC had never seen. Nobody expected journeyman MTB to beat him. He did.
    

12. 12

    

    Diaz vs. Gomi

    Fight Ends in a No Contest  |  Pride 33

    After Diaz's stint in the UFC, he enters Pride a huge underdog against Lightweight champion, Takanori Gomi. After his win with the gogoplata, Diaz's career seems to jump off again.
    

13. 13

    

    Story vs. Brenneman

    Charlie Brenneman | Decision  |  UFC on Versus 4

14. 14

    

    Emelianenko vs. Silva

    Antônio Silva | KO/TKO | Round 2  |  Strikeforce

    After Fedor's first loss, he was expected to rebound by winning the Strikeforce Heavyweight Grand Prix. However, this was stopped short when he was eliminated in the first round.
    

15. 15

    

    Penn vs. Edgar II

    Frankie Edgar | Decision  |  UFC 118

    Even as a champion, Frankie Edgar was the underdog in his rematch title fight against BJ Penn. He proved everybody wrong again as he won even more convincingly than the first outing.
    

16. 16

    

    Sokoudjou vs. Nogueira

    Rameau Thierry Sokoudjou | KO/TKO | RD 1  |  Pride 33

    Sokodjou had maybe 5 fights at the time he fought highly touted Rogerio Nogueira, brother of Rodrigo Nogueira, in Pride, and knocked him out in a career defining moment.
    

17. 17

    

    Sokoudjou vs. Arona

    Rameau Thierry Sokoudjou | KO/TKO | RD 1  |  Pride 34

    Sokodjou's career is full of upsets mainly because he loses seemingly every other fight. He pulls another upset in the final Pride show against Pride superstar Ricardo Arona.
    

18. 18

    

    Rogers vs. Arlovski

    Brett Rogers | KO/TKO | Round 1  |  Strikeforce

    Former UFC Heavyweight champion was looking to rebound after an embarassing KO by Fedor, against virtual unknown Brett Rogers. Apparently, not the best rebound opponent.
    

19. 19

    

    Yamamoto vs. Warren

    Joe Warren | Decision  |  Dream 9

    Former Hero's champ Kid Yamamoto faced MMA newcomer Joe Warren in DREAM's FW Grand-Prix. Yamamoto was expected to run through him, however he lost via decision.
    

20. 20

    

    Couture vs. Gonzaga

    Randy Couture | KO/TKO | Round 3  |  UFC 74

    Both men's previous fights were in the top 10 upsets on this list, which scheduled them against eachother in this title fight. Couture pulled off the upset against the up and coming Gonzaga.
    

21. 21

    

    Golyaev vs. Gomi

    Sergey Golyaev | Decision  |  Sengoku 6

    Sherdog's upset of the year 2009 has gatekeeper Sergey Golyaev beating arguably the LW GOAT.