Early on in OPM, Saitama dreams of a fight between himself and the king of the underground-dwelling people who are invading the surface. In that fight he feels as though he has met his match and he's pushed to the very limits of his power.
Only he wakes up, it all having been a dream. Actual subterraneous invaders show up, but nothing like what he dreamed about.
As it turns out, the final fight of the season with Saitama vs Borros is an exact mirror of that dream fight. Only in this regard, Borros makes the moves that dream-Saitama did.
Food for thought!