Superman was stunned by a falling car during the Metropolis fight and had his head knocked back by a Gatling gun round from Colonel Hardy's helicopter in Smallville. Based on the strength of the Bifrost bridge, which withstood the crash of a multi-ton Dark Elf ship in TDW but was visibly damaged and, ultimately, broken by multiple blows from Mjolnir in the first Thor, I would give the fight to the God of Thunder.