I have saved a number of people, but not in the way that you may have in mind here. I have saved some from the clutches of religious belief-system brainwashing--something which happens all over the world, most unfortunately.
As far as saving someone in the sense that you may be looking for, only once...or twice? (for all I know) In a rock climbing situation, I talked a stuck and beginning to panic climbing member out of it, and into safety. I talked ( and physically prevented) my previous wife (a Japanese national too) from going out into the streets of Detroit, Michigan (USA) one night, to find a person who had stole her jewelry box. ( a long story otherwise, but it did happen...and I did prevent her from going out there...although it took half the night)