Without Vegeta's knowledge, Kakarot has managed to escape the dying Planet Namek during Vegeta's battle with Frieza. When Vegeta returned to find a pod to help him escape, he found out that one of the Ginyu Force's pods were missing, he figured that Goku must have escaped the planet after everyone on it (including the helpless Bulma) was slaughtered by his hands, and that his lack of knowledge in the programming of the pods must have caused him to go to the next set destination programmed into it...and thus Vegeta followed Goku in his pod to the planet Yardrat.
A fight ensues, and luckily for Goku, the difference in time between his and Vegeta's journey allowed him to recover from the injuries and eat some food on planet yardrat. Goku had gained a Zenkai boost, putting him on par with Vegeta.... After a while during the fight, Vegeta's taunts to Goku about his dead friends caused him to explode in rage and transform into the Legendary Super Saiyan. Not wanting to give up or destract himself with the fact that another saiyan reached the legendary transformation, Vegeta immediately attacks and uses his full power as a super saiyan, after avoiding a kamehameha from Goku, who keeps on using everything he's got to blast Vegeta. His recklessness in using his energy reservoirs to defeat Vegeta as fast as he can backfires and his injuries start hurting even more, causing his energy to rapidly decrease; at that point, Vegeta teleports away from Goku's attack and blasts him with a Double Galick Gun from behind, knocking him out of his Super Saiyan transformation. Vegeta finishes him off by beating him down with numerous hits all over his body as an act of humiliation, leading to the noble saiyan's death, and the dark prince's reign over the universe.

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