Le Fondre, introduced by McDermott after 69 minutes, scored twice in the final six minutes of the game as the visitors paid the price for the early sending-off of defender Zac Thompson.
“If you want someone to score a goal for you to win a game, we’ve got the perfect man and he’s done it again today,” McDermott said. “He’s learning all the time and he’s a natural finisher.”
Elsewhere West Ham moved to within three points of second-placed Southampton with a 4-0 win at Barnsley.
The Hammers, who started the game seven points adrift of Reading, never looked back once midfielder Kevin Nolan tapped the ball home in the sixth minute after Nicky Maynard’s corner had bounced between Barnsley striker Craig Davies’ legs.
Maynard added a fine second with a low finish from the edge of the penalty area after a neat interchange with Nolan in the 23rd minute. Mark Noble cashed in on more hapless defending 12 minutes later to curl home a third goal from a tight angle before Ricardo Vaz Te added a fourth from close range against his former club early in the second half.
Blackpool moved level on points with fourth-placed Birmingham following a 2-0 win at Watford, Stephen Dobbie getting both goals.
Brighton occupy the final play-off place but they had a disappointing afternoon, losing 1-0 at Burnley, the only goal coming from Charlie Austin.
Manager Gus Poyet left the touchline before the end of the game in fury as Brighton drop out of the play-off places ahead of today’s clash between Middlesbrough and Cardiff.