A girlfriend once tried something like that with me, in a dark second floor hallway when I came up the stairs at night. Problem is I couldn't see who she was in the shadows, and being it was my sister's house where I was vacationing, and my GF was staying elsewhere with her own relatives nearby, I thought I had the empty house to myself, though I'd lent her a key.
I was an Army Captain at the time, and I reflexively screamed a martial arts shout and attacked, my hands stopping literally an inch from her face when I recognized her at the last second. She moaned and collapsed to the floor in a dead faint! Honest to gawd!
Fortunately the floor was heavily carpeted and she wasn't hurt. We laughed about it afterwards when she'd recovered, but neither did she ever try such a trick with me again. I seriously warned her that I was about to deliver a lethal blow (forget silly movies where the fighters receive unlimited bone-crushing hits and aren't phased); our training teaches us how to kill on the first strike, not have a prolonged, beautifully choreographed hand-to-hand duel for the cameras.
The longer you fight the more likely you'll lose, expending strength you'll need later, even if you do defeat your opponent. You kill quickly & efficiently, and move on. In many ways it's a pure Ninja philosophy.
She said what really scared her was my shout, in an animal-like voice she'd never heard before, from me or anyone, and also my lightning reaction without any warning or delay. And of course that's the idea, what we were taught to do in the Army, but I was surprised myself how I reacted automatically without thinking, like a classic knee-jerk reaction.
Moral: be careful when you try such stunts, and who you play them on. You may get more than you bargained for.