Other source:

As his friends run for cover, Goku prepares to take Piccolo’s final attack. Piccolo unleashes a giant wave of energy comparable to a nuclear explosion, leveling the entire island. As the dust settles Goku is still standing. He takes advantage of Piccolo’s weakened state after his huge energy expenditure and knocks him into the ground with a Kamehameha. Just as the count reaches nine, Piccolo lifts his head and emits an energy beam impaling Goku–but he won’t give up just yet.