Well i can think of possible scenarios for sasuke to win. Sasuke aint easy in taijutsu and tobirama has no kunais. Paper tag jutsu is a Draw. Manda is rather big and tobi has no other strong offensive.
But due to the hype and all the loving tobirama fans...( ah **** it, Sasuke wins)
Anybody got an actual argument for Tobirama?
If Tobirama can mark Sasuke, he can end him with Hiraishingiri to the skull or neck. Anywhere else and Sasuke uses Oral Rebirth, and Tobirama will not be getting a second chance to mark him. Of course, Sasuke beats him more times than not imo. I just don't see Tobirama doing much to him otherwise.