10-man Lincoln held firm under intense second-half pressure as the Imps claimed all three points against fellow play-off chasing side York City courtesy of Ben Futcher’s strike.
Futcher netted from Mark Bailey’s cross from the right, the defender powering home a header past keeper Phil Whitehead.
York should have gone in front after just six minutes when Imps defender Paul Morgan gifted a chance to John Parkin. However, the striker hit his shot too close to keeper Alan Marriott.
City went close again 11 minutes later when Lee Nogan shot wide from three yards after Marriot could only push out an inswinging corner into his path.
Lincoln saw their numbers reduced when Chris Cornelly was dismissed 10 minutes into the second half for two yellow cards.
York, with a strong wind behind them, laid siege to the Imps goal but could not force the ball home.
Parkin wasted two half-chances before seeing a low shot from five yards saved by Marriott.
Parkin got behind the Lincoln defence again in stoppage time only to shoot wide from close range, while Stephen Brackstone’s 20-yard effort was tipped over by Marriot.