Style wise this is a good match up for Kostya Tszyu, if you allowed Kostya Tszyu mid-distance range where he could time you with his power shots. And lets face it Kostya Tszyu had excellent timing, he was very effective.

Fighters who smothered him, and didn't allow him room to get punching distance. He struggled against forgetting if he was past his prime or not right in this fight or that fight, he still had trouble with that type of opponent end of.

Now Manny Pacquiao does fight at mid-distance, which would give Kostya Tyszu a chance. It really would depend on how well Manny Pacquiao could take the shots. But IMO its a close match up i think style wise its winnable for Kostya Tszyu, but it really could go either way.