Dragon Ball Z Episode 45: Frieza Strikes!
Episode 45 of 291 of Dragon Ball Z, aired April 25, 1990, 25 minutes. Available with English subtitles and dub where released.
Episode summary
While Bulma, Krillin and Gohan discuss what to do next, Frieza sends two soldiers to inflitrate their ship. But Krillin and Gohan's combined might is too much for them to handle, and they are easily defeated. Meanwhile, on another part of the planet, Vegeta defeats his longtime enemy, Cui.