The two are going blow for blow building explode miles away from the air pressure of the punches alone. Saitama "This is what I always wanted! This thrill! THIS IS A REAL FIGHT!" The two seem to be stalemating and Freiza tells him "I never knew how exciting fighting could be! No wonder those monkeys love it so much!" When Freiza starts to lose he gets desperate and flies up "There's still one way I can beat you. I can breathe in space and you can't. If I can't beat you with force I'll blow up this whole planet! So I at least know you'll die with me!" He shoots a large death ball but it's sent back with a serious headbutt. Freiza's entire lower half is incinerated and he falls to earth barely alive. Saitama punches him one last time, finishing the job. "Wait. I just killed my only equal which means. I'M BACK TO ONE PUNCH AGAIN! NOOOOOOOOOOOOOOOOOOO!!!"