The problem with debating against One Punch Man in general, is that most fans don't seem to realise that in VS Debates and Hypothetical Battles, we take the feats demonstrated, or at least implied by the actual medium. Word of God works only for story, not for debates. read more
Boomstick: Arriving from the Gorath asteroid, which impacted Tokyo, Monster X and Godzilla fought, before it transformed into Kaizer Ghidorah. Wiz: After a seemingly losing fight, Godzilla unleashed his full potential and shot Kaizer into space, destroying him as Gordon destroyed the Xillians. read more
Saitama can take the first two rounds easily but InHell no-sold a Space Godzilla who could, when clashing with Godzilla, planet-bust. Saitama's best offensive feat is splitting a planet-busting attack, so he should be able to do some damage, but not a huge amount. Saitama narrowly takes this, I beleive, due to his massive speed advantage. read more