Longford Town 1 Derry City 0
Paul McNally earned Longford a priceless win in their battle to avoid relegation with the only goal of the game.
Defender McNally stayed up following a free kick on 33 minutes to beat the Derry offside trap onto Danny Spiller's pass and shoot past Russell Payne.
Derry, who twice hit the Town woodwork through Jamie Hughes and Liam Coyle, had left-back Sean Hargan sent off on the hour for a wild challenge on man-of-the-match Spiller.
Town remain in the play-off place but are now seven points ahead of third bottom Dundalk whom they meet at home next week.