That's what I say, too... Savatage was (I think) the first band to be called "power metal", back in the 80s,
Metallica were the first band to coin the term, with a demo of the same name.
Pantera a few years later titled an album "POWER METAL"
Though, obviously, neither band fits the mold of what most people today would consider to be power metal.
By today's definition of power metal, I would think early nods would have to go to Jag Panzer, and maybe even Grave Digger.
Helloween were speed before power (once again, that is power by "today's" definition).
Savatage in the 80's were, like many bands, a bit lost in the mix.
They were too light for the die hard thrash scene, and too heavy for the glam scene. I dunno, I always just thought of them then as a more technical thrash band, though obviously their sound has evolved a lot since Sirens, Hall, etc, etc..... Never considered them to be a power metal band though.