Over pair to the flop

I was wondering if I still had fold equity after the flop once the villain went all-in.  Historical data is that we were down to the last 28 people after the redraw and should I have folded since we were heads up in this hand after the flop?  I did not put him on a set after the flop but had an over pair to the board.  Could I have gotten away from this had after C-betting the flop heads -up with an over pair to a semi-coordinated board?