Vegeta first uses the attack while training in his Capsule Corporation spaceship. Vowing to surpass Goku's strength, Vegeta's 300x gravitytraining has him hit by one of his own energy blasts to which the Saiyan prince unleashes the Galick Blazer attack, causing the two ki blasts to clash into each other and explode the spaceship with him still inside. Much to Bulma's and Yamcha's shock, Vegeta emerges from the rubble albeit severely injured.
Vegeta later uses the Galick Blazer to attack Cell during the Kamehameha Energy Clash between Cell's Solar Kamehameha and Gohan's Father-Son Kamehameha; the Super Saiyan Second Grade was successful in distracting the android and allowing the Super Saiyan 2 to muster the power to defeat Cell.
Appearances in games
Galick Blazer was named in Dragon Ball Heroes, where it is Super Saiyan 3 Vegeta's ultimate attack. It also appears in Dragon Ball Z: Battle of Z, used by Super Saiyan 2 Vegeta, except it is a continuous version.