Le Dernier Combat

Goku turned out to be just testing Piccolo's attacks, as he usually does. As they resume battling, Goku seems to be superior to his opponent. Getting worried, Piccolo decides to unleash a devastating attack that will wipe out everyone at the tournament. Krillin reminds Goku that even if Kami dies in the course of destroying Piccolo, they always have the dragon balls to revive him. Realizing this, Goku combats Piccolo's blast with his most powerful Kamehameha.  (Source: Wikipedia)