Jonson Clarke-Harris struck late on to give Peterborough a 1-0 Sky Bet League One win at Fleetwood.
The division's leading scorer had been shackled for most of the afternoon but drilled a free-kick inside the post with three minutes left on the clock to maintain Posh's title charge.
Peterborough should have taken an early lead when Clarke-Harris made the space for a shot from 12 yards out. Cod Army keeper Alex Cairns spread himself just enough to somehow deny the forward.
Although Fleetwood took around half an hour to assert some pressure, they should have led at the break, with Ged Garner and Wes Burns spurning close-range chances.
Garner poked the ball straight into Christy Pym's hands from a few yards away, and Burns, with just about the last kick of the half, knocked over the bar at point-blank range to see the teams go in at half-time level.
In the second half it was the Cod Army that created the best openings, with Sam Finley seeing his thumping drive pushed to safety and Danny Andrew crashing a shot against the bar, thanks to a deflection off Frankie Kent.
But when he was presented with a chance to strike a free-kick from the edge of the box, Clarke-Harris scored his 26th league goal of the season to break the hosts' hearts.