Portadown moved to within three points of the Premiership summit thanks to this away victory over Coleraine.
Mark McAllister scored the only goal on the stroke of half-time with a powerful header from Chris Casement's cross.
Ports keeper Billy Brennan kept out three Ian Parkhill efforts early in the second half and he tipped over from a Steven Douglas free-kick.
At the other end Darren Murray broke clear but keeper Michael Doherty deflected his shot over the bar.
Coleraine midfielder Joe McNeill dragged an early shot wide while Michael Gault headed wide for the visitors.
Brennan made a point-blank save to deny McNeill before McAllister broke the deadlock with a bullet header from Casement's pinpoint cross.
Parkhill wasted Coleraine's best chances after the break with the forward breaking clear but Brennan blocked his initial shot.
The keeper repeated the feat from the rebound before watching Parkhill's third attempt drift over.
Parkhill wasted another opportunity when he headed straight at Brennan from a McNeill cross.
Coleraine pressed for the equaliser while the Ports threatened on the counter-attack and Doherty palmed Murray's shot onto the roof of the net.
The win takes Portadown up to third and two points behind Crusaders, who defeated pacesetters Linfield 2-1.
"It was a crucial win - we dug in, kept a clean sheet and all the boys are delighted," said match-winner McAllister.
"We will be underdogs for the title but if we can build on this then we have a wee chance.
"We want to secure European football and if anything else happens it will be a bonus."