Gregory is a very fast little guy and even Goku had a tough time catching him. That being said, the difference in striking power will be decisive here. Gregory can land thousands of blows on Goku and they would have no effect. On the other hand, Goku could just power up and his aura should be enough to blow Gregory away. I don’t see how the little guy could ever hope to win the round and for those reasons…he’s out. Goku wins.