I just used an unending mix of jump kicks, bicycle kicks (lots), and low fireballs. Stay out of the corner, and don't be afraid to pressure him on wake up.
Both fights were pretty easy because you can use the same tactic the entire match to win. It's just a matter of finding that tactic.
As many have already stated, as Liu just spam low fireball from max range. As Raiden, wait for a projectile, teleport and punish. I used 1,2,1, shock, superman for about 11% damage and that was plenty.