Luke Waterfall scored an own goal and was sent off as Grimsby suffered a shock 3-1 home defeat to Maidenhead.

A draw would have been enough for the sixth-placed Mariners book their place in the National League play-offs.

But Waterfall put through his own net for the second successive game after 25 minutes and was then dismissed 60 seconds later for preventing a goalscoring opportunity.

Sam Barratt converted the resulting spot-kick and Ryan Upward added a third Maidenhead goal after 68 minutes.

Tristan Abrahams reduced the deficit 15 minutes from time from the penalty spot after being pulled to the ground.

Grimsby have two games left, against Boreham Wood and Eastleigh, to book a play-off spot.