Quote Originally Posted by Devonix View Post
Exactly, goku took it seriously but that's not the same as using all his energy. Krillin was pushing himself to his limits. Look on goku's face, he was surprised that he had to put in as much effort as he did.
Considering the previous gap in their power levels, and just how much raw power Goku has... being able to make Goku struggle, if only for a moment, says a lot about Krillin and hoe far he's come.