Who's the lighter punching guy? Pac? Kostya never fought Pac so all you can do is guess the outcome. Pac KO 1 is just as likely as anything.

The facts are..

Kostya was stopped TWICE at 140. Fact.

Hatton beat Tszyu. Fact. Hatton even beat the other guy that beat Tszyu. Fact.

Kostya has NO excuses. Fact.

Kostya is overrated. IMO. Fact.