In the manga, Gohan never managed to defeat Goku. Their battles often ended with Goku coming out on top or the fight being interrupted for some reason.
In my opinion, it's highly unlikely. Goku has mastered multiple forms and techniques that give him a wide range of powers. Saitama's one-punch style might not be effective against Goku's diverse skills and battle experience.
In fanfiction, Bardock and Omni - Man are often combined in interesting ways. Bardock is from the Dragon Ball universe, known for his sacrifice. Omni - Man from Invincible has his own complex character. In fanfics, they might be pitted against each other in battles of strength. This can lead to exciting scenarios where their different powers and personalities clash. It also allows for exploration of how their respective moral compasses would interact in a fictional crossover.
Well, Omni Man's story in comics is full of surprises. He might switch allegiances, undergo power changes, or face unexpected challenges that force him to evolve.