Dragon Ball Z - episode 61 - 11 Sep, 1990

Krillin and Gohan finally make it to Guru's place, but Vegeta has followed them, determined to get the last Dragon Ball. As Krillin tries to hold off Vegeta, Gohan has his hidden powers unleashed. Suddenly, they all sense an incredibly powerful force arriving on the planet. Vegeta recognizes it as the Ginyu Force. He tells Krillin and Gohan that the Ginyu Force is far more powerful even than himself. Vegeta says that if they are to defeat them and prevent Frieza from making his wish, they must work together. (Source: Wikipedia)