It depends, I think. With a 2 hours / 40 moves game, the 2000 player with an extra Knight (or Bishop) would win, I am quite sure.
But with a 3/0 game, or something like that, Kasparov would win : it is very easy to make a lot of errors when you play quickly.
I assume most ~2000 female players could have beaten fischer with decent time available.
Furthermore, exchange odds + pawn aka (wn for br + f7 pawn).