I can see this fight going like this:
let's go guys
2-3 punches from both fighters and one leg kick from werdum
Nelson catches Werdum
case 1) Werdum pulls guard cause he submitted Fedor so everything is possible for him (in his opinion) and Nelson stays at top of him for the rest of the round
Case 2) Nelson takes him down with his weight and stays on top for the rest of the round.
Now, choose case 1 or 2 for each of the 3 rounds and the sum is: Nelson 30-27 via UD.
(now you clap)