Just for fun, I would say there are many ways, and it depends on the tone of your story, too. If it's a shonen anime like Dragon Ball in your example, discovering that secret hidden power at the last minute and going Super Saiyan sure will fix that.
Think on Fantasy clasics like LOTR, where in The Two Towers they are surrounded at Helm's Deep and about to lose, when the horn sounds, and Gandalf arrives with backup in the form of Eomer and all the loyalists who had departed in exile now come back in the nick of time to turn the tide of battle. Or on a smaller scale in Game of Thrones, Jon Snow does die, but is resurrected, kinda like Gandalf...ish.
I mean, depending on how you write it, you can maybe even make a compelling argument for a single warrior at the end of his rope to pull strength from his conviction and power through to finish and win the fight. Hell, even John Wick does that in the last one, walking those impossible stairs full of dudes to fight...and he does! Execution matters, and if you can get your audience to suspend their disbelief in your method, that's what you need to do.
