Now, I'll retract my last statement about Enma winning, but I generally can't see him losing there. Perhaps it's the Japanese/Buddhist favoritism, but I don't think Death will win.
Damn, I missed a few chapters. Death is really cool but I think he's gonna lose unless we get Enma's backstory next chapter.
Remember: The author can't have them play ALL their cards in their first fight since they'll have to fight again and Death clearly played all of his now.
That doesn't mean anything since all the fights aren't 'to the death' here. Morrigan showed up after all and she can't have won the tournament since Zeus took that spot.