Bardock fighting Freiza
Instead of dying, Bardock fought King Vegeta and defeated him, becoming the new king. He then went and challenged Frieza while the rest of the Saiyans surrounded the ship and killed every single one of Frieza's men who came to fight them. While fighting Bardock, Frieza reveals that he will destroy Planet Vegeta and kill every saiyan there. This causes Bardock to become an SSJ. He then kills Freiza and his men.
Bardock after transforming into an SSJ, about to kill Freiza
Afterwards Bardock flees the ship, then him and the Saiyans destroy it.