I think Watson would outbox him to take the decision by the way, but wouldn't have it entirely easy. Collins: whilst a very good fighter, with a great chin and power, he faced and defeated Eubank and Benn when both were on the downslope (particularly 'Nige). Watson: UD (relatively close)
I think Watson would box rings round him, but with the occasional round where Collins would rough him up and take the round. Still, I see Watson hanging on and winning a comfortable 12 round decision.