Champions Linfield clocked up a record points total in the Premiership as they ended the league campaign on a high.
Blues captain Noel Bailie, playing his last league game after 1,013 appearances, lifted the Gibson Cup at Windsor Park.
It was a low-key affair with the Ports striker Matthew Tipton twice denied by the woodwork.
Curtis Allen fired in the only goal from close range on 81 minutes, taking Linfield to 85 points.
Tipton fired against the underside of the crossbar from one of Philip Craig's long and dangerous throw-ins.
Linfield also came close in the first half with Jamie Tomelty heading staright at keeper Aaron Hogg from six yards.
Blues defender David Armstrong was stretchered off early in the second half with a leg injury and he is a major doubt for next Saturday's Irish Cup final against Crusaders.
A defensive blunder let Allen in for the goal, a back pass hitting a post and the striker pounced to hammer home the rebound.
The Ports should have levelled late on but Tipton managed to hit the bar from two yards.
Linfield have made a fitting tribute to Bailie by retiring his number 11 shirt.
"I've had some incredible memories and this is another great one," said the 40-year-old.