http://www.fightmatrix.com/2008/06/28/ten-biggest-upsets-in-mma/ We’ve compiled a list of the 10 biggest MMA upsets in recent history. The significance upsets on this list is measured not by the betting odds, but by the difference in the Fightmatrix.com point standing between the two fighters, normalized for weight class differences.
1. Gabriel Gonzaga defeats Mirko Filipovic (UFC 70, Apr 21 2007) @ -186.18
2. Matt Serra defeats Georges St. Pierre (UFC 69, Apr 7 2007 ) @ -155.02
3. Quinton Jackson defeats Chuck Liddell (UFC 71, May 26 2007 ) @ -142.45
4. Mark Hunt defeats Wanderlei Silva (Pride Shockwave 2004, Dec 31 2004 ) @ -140.3
5. Keith Jardine defeats Chuck Liddell (UFC 76, Sep 22 2007 ) @ -127.90
6. Mark Coleman defeats Mauricio Rua (Pride 31, Feb 26 2006 ) @ -126.49
7. Cheick Kongo defeats Mirko Filipovic (UFC 75, Sep 8 2007 ) @ -114.57
8. Forrest Griffin defeats Mauricio Rua (UFC 76, Sep 22 2007 ) @ -108.48
9. Eduardo Dantas defeats Shinichi Kojima (Shooto, Nov 8 2007 ) @ -103.79
10. Sokoudjou defeats Antonio Rogerio Nogueira (Pride 33, Feb 24 2007 ) @ -98.48
Interesting to note that with exception of 2 fights, this list is all comprised of heavy and light-heavyweights. Also, Mirko Filipovic, Chuck Liddell, and Mauricio Rua were all victims of huge upsets on more than one occasion.