Dragon Ball Z Episode 129: Upgrade to Super Saiyan
Episode 129 of 291 of Dragon Ball Z, aired February 26, 1992, 25 minutes. Available with English subtitles and dub where released.
Episode summary
The fight begins as Goku turns Super Saiyan and fights Android 19. It looks like Goku has the situation handled, but he discovers 19's aborbing technique after firing a Kamehameha. To make matters worse, it looks like something else is weakening him while 19's ready to fight.