Superman beating Goku
As far as I can remember when he defeats freeza, freeza taunts him to go around looking for a ship which he can start, because he can’t breathe in space, where as freeza can. So I am going to assume he can’t.
I am also assuming that he doesn’t have krypotnite because a) he isn’t that smart and b) He fights fair. He gives cell a sanjo bean before cell fights Gohan, because otherwise its not a fair fight.
Assuming Superman can at most lift 100 tonnes (correct me if I am wrong)
Scenario: Barren planet with yellow sun, breathable atmosphere. Assuming Majin Superman or superman under control of Poison Ivy for the sake of battle.
Round 1: Normal goku starts fighting, Powers up and unleashes punches. Both are fast but I am going to assume superman is faster than Goku at nearly all points. Superman blocks punches returns with punches. Goku gets hit a few times. Goes into Kiyokane mode, Superman allows because he also fights fair. Goku’s blocking and hitting is now much better. He has faster speed and the advantage of being actually trained in martial arts. (Superman has no such training). Superman gets hit but a standard Goku punch doesn’t have much force (I am assuming it can lift a 1-5 tonne weight but not more, as his training in the kai world happens). Superman tries to use laser eyes and frost breath but goku is fast enough to dodge. Goku fires kamehameha but superman’s frost breath blocks it. Desperate straight attack. He punches superman in stomach but gets blown away by his return kick. Superman laughs at the his attempts and goku smiles as he wipes blood. Round superman.
Round 2: Goku goes Super Saiyan mode. Still possibly slower than superman but nearly as powerful (Goku as Super Saiyan lifts the weights with kai with no issues). Maybe slightly still less powerful but still powerful enough to cause damage. Superman’s parries are well blocked by goku’s martial arts training, except for an occasional blow. Goku defends mostly, but releases an occasional punch damaging superman. The two finally separate, Goku charges up Kamehameha, superman allows because he underestimates the techinque. Goku fires, superman is is still oblivious to its power, tries frost breath, fails and gets hit substantially. Superman is now slightly tired, his smile wiped off, whereas Goku now has a smirk. Round Goku.
Final Round: Goku has had enough of this nonsense, powers up to level 3, says he is more powerful and finally goes straight to level 4. Superman’s strength is no longer a match for Goku’s strength. Speed nearly equal, but fighting abilities make all the difference. Superman tries to fire full power punches every time, which slows down his parry rate. Goku evades and blocks for fun before return kicking him. Superman is blown away at a distance, looks at Goku. Goku smiles, instant transmission. (instant transmission happens at light speed. but in a different dimension. Only start and end points are in same dimension, so even superman’s super vision can’t see it.) Goku disappears and appears right in front of him, battering him with volleys, superman tries to block them but is very rarely successful. He is getting badly beaten up. Tries laser eyes at small distance but goku evades. Superman tries to fly away and gain distance. Goku starts charging kamehameha. Superman knows he can’t handle kamehameha plus instant transmission, so flies back in. Goku fires, superman dodges half allowed by Goku intentionally firing it slightly wide. Superman punches goku with whole strength Goku gets knocked back. Superman tries to volley punches, goku dodges some, blocks some, and finally lets him hit some to show off total dominance. Superman though using full might, is already tired, volley doesn’t have much power. Tries power punch, which Goku spots and blocks and counters. Fires in a elbow from top to send Superman crashing into the ground, several meters inside. Round Goku total dominance
By now we have a clear winner. But to induce a fatality, Goku starts charging a spirit bomb, doesn’t need much power as superman is already in shit state. Superman finally climbs out, sees Goku preparing an attack, unguarded with arms above, charges blindly with full power. Goku is waiting for this moment.