Dragon Ball Z - episode 22 - 10 Oct, 1989

The Saiyans Vegeta and Nappa defiantly announce their arrival on Earth with the complete destruction of East City. Sensing their power, Goku, Gohan and Krillin prepare for the worst and meet the Saiyans face to face where Piccolo learns of his origins on the planet Namek. Yajirobe also learns of the Saiyans arrival but uses it merely as an occasion for profit. Our heroes are left facing on onslaught of sprouted Saibamen under the grinning command of Vegeta and Nappa. (Source: silvershenron)