As a Null, Spongebob nullifies all powers of opponents. So, Gojo's powers are nullified when facing Spongebob. Even though Gojo is a skilled jiuitsu sorcerer with powers like “Infinity,” and “Cursed Technique Expansion: Blue,” he cannot use any of them against Spongebob. Moreover, Spongebob can erase all fictional beings and control the judge, which gives him an upper hand in this fight. As Gojo's powers are nullified, he is defenseless in this battle and hence, Spongebob wins.