Pompey twice fought from behind to draw an enthralling contest with Derby at a wet Fratton Park.
The 2-2 stalemate means the hosts maintain a five-point gap to their opponents at the top of the League One standings.
Abu Kamara finished a fine passing move for John Mousinho's side, although that was sandwiched by a couple of Joe Ward strikes.
But Owen Moxon came off the bench in the second half to hit a stunning strike and ensure the spoils would be shared.