Diaconu and Dawson are totally different fights. Dawson would win by UD no problem. Pascal won this fight because he was much faster than Diaconu and he wouldn't have that advantage against Dawson. Like Silencers said, Dawson is better at everything.
Pascal gets stunned in almost all his fights I've seen him in. He got stunned by a grazing punch from Diacnu. He also got stunned a couple of times against Froch, and was stunned against Pittman...
I think Dawsons speed would cause Pascal problems because it would be the fastest fighter Pascal has ever fought, and the punches that hurt the most are the ones you can't see coming.
Dawson would have an edge with his jab.. Great jabs mean hell for Pascal. They are the one punch that he has a lot of trouble slipping. He does this akward Ali-esque head movement that leaves him off balance and out of position to punch (and open to a punch, obviously).
I dont think Dawson would KO him but Dawson is a much different kind of fight and I think he would be the first fighter Pascal would fight that could match him in EVERY department and he's better from a technical aspect.
I'd say Dawson via UD