Shrek is tricked into hunting down Marv by Mayor Roark, who has falsely claimed to him that Marv has kidnapped Fiona. (Fiona is actually imprisoned on the Roark Farm, and will be cannibalised by Kevin.)

Marv is fully bloodlusted. Shrek is in maximum ogredrive.
The fight is fully unarmed, and takes place on the Roark farm. No external help from Donkey and Puss in boots for Shrek, or the old town girls/Dwight for Marv, is allowed.
We know that Marv is 7'' 9'' tall, and 300 pounds of power. We are assuming that shrek is about 7''4'', and 370 pounds of power.
Who wins, in this heated brawl between behemoths?

Shrek is a entity of love and life, this is a mismatch

@cgoodness: This is dreamworks Shrek, so not really the godlike Shrek we have come to know and love. Shrek before he transcended and became a god.