Sergio Non does the leg work:

...the history of relatively quick rematches at the elite level suggests that the first result tends to repeat itself.

Fighting Stances looked at the outcomes of notable rematches involving high-level competitors from the Ultimate Fighting Championship, Pride Fighting Championships and Strikeforce.

...

It takes less than two full hands to count the number of notable rematches or trilogies at the elite level that ended with a different result:

1. Dan Severn - Ken Shamrock
2. Tito Ortiz - Guy Mezger
3. Royce Gracie - Hidehiko Yoshida
4. Chuck Liddell - Randy Couture
5. Kazuo Misaki - Dan Henderson
6. Takanori Gomi - Marcus Aurelio
7. Antonio Rodrigo Nogueira - Josh Barnett
8. Tim Sylvia - Andrei Arlovski

In contrast, he tallies up 16 rematches where the winner of the first fight took the second, five trilogies taken by the winner of the first fight, three fights where the fighter winning the majority of the first fight before being submitted or suddenly KO'd came back to win the rematch, one rematch won by the loser of a controversial decision (Shogun vs Machida) and four inconclusive rematches.

I have to think that B.J. Penn may be in the Shogun Rua position of having lost a controversial decision. Benevidez, not so much. 

These numbers make me appreciate the legendary three fight series between Randy Couture and Chuck Liddell all the more.