Other source:
West Kai suggests that an Otherworld Martial Arts Tournament be held to determine which quadrant has the greatest fighter. The Grand Kai agrees, and so the Tournament begins. After several matches, it is Goku's turn. His opponent grabs him and starts to tickle him into submission. Goku gets in a hit on him, and this causes his opponent to cry and start his metamorphosis into his ultimate form. But because this metamorphosis takes 1200 years, Goku is declared the winner by default.
