Shaun Rooney scored his sixth goal of the season to earn improving Fleetwood a 1-0 Sky bet League One win over struggling Cambridge.
The visitors had looked most likely to score first, with Sam Smith hitting a post and Jack Lankester denied by Jay Lynch.
And Fleetwood, now up to 13th, had not managed a shot on target as they struggled to break down the Sky Blues.
Cian Hayes looked to have wasted their best effort when he delayed his shot with keeper Dimitar Mitov off his line.
Instead, Scott Brown's Cod Army found a way to grab a fourth win in five games in all competitions with a goal two minutes from time.
Substitute Josh Earl provided the assist with a fine left-wing cross and defender Rooney's header from five yards had the home fans celebrating.
Cambridge's latest defeat, after the encouragement of last weekend's win over Oxford, leaves Mark Bonner's side second from bottom though only two points from safety.
Even after Rooney's decisive strike Cambridge might have snatched a point but Smith slid the ball wide late in stoppage time.