Can someone ID this horror movie?

OK, first off, it’s a vampire flick. It’s in color, and I’m guessing it was made in the 70’s or maybe early 80’s.

All I remember is the last scene. The hero rescues the girl, kills the lead vampire with a wooden stake (big surprise there), and runs away with the girl as the vampire’s face decomposes. They’re running through the castle, but for some reason, they stop and you see the guy holding the girl’s hand (The rest of her is offscreen) . . . and then you see the hand slowly pull away from his grasp. Without looking around, the guy starts shaking his head and groaning “Oh no.”

Cut to the face of girl–who is revealed to be a vampire–lunging at the camera. The camera freezes in mid lunge. The next scene shows the bloody body of the hero with a surprised look on his face. You here the voice of the lead vampire say “Superstition?” and then his evil laugh. End of movie.

If any horror freaks could help me with this one, I’d be much obliged. Thanks.

Count Yorga, Vampire
I had a huge crush on Robert Quarry.

You rawk, peri. Thanks so much.