If the Sponge's Venue is the Sea Bed (Fixed Ala James Scott and Rahway) Than i suspect the Sponge could beat whatever heavyweight challenged it - A Sponge could beat Marciano's 49-0 Record... - But it might get upset by an Ivory Coast Pearl Diver ??? ( I think this is called entering into the Spirit of things - but will not commit to Audley Bashing... !)
Harrison wins a decision, but when leaving the ring, slips on the sponge and knocks himself out via the turnbuckle.