Greencastle were presented with the Jackie Crossan Premier Division title as the Chapel Lane side recorded their 15th League win on the trot.
Carn FC 1 Greencastle FC 6
Greencastle got the first chance on 8 minutes when Eamonn Donnelly found Nigel McMonagle on the right side of midfield and he went on a brilliant run rounding the defender but failed to hit the target from 10 yards.
Carn replied on 14 minutes after Shane Doherty broke on the left wing and squared it for Cade Cooke but his low shot was well saved by Dylan Doherty in the Greencastle goal.
Greencastle broke the deadlock on 29 minutes when Christy Hegarty released Nigel McMonagle who went on a great run rounding the defender and slotting it to the bottom of the net from 12 yards.
Greencastle doubled their lead on 32 minutes after Christy Hegarty broke on the left wing and crossed it for Conor Gillen who drilled it to the bottom right corner of the net from 15 yards.
It was three for Greencastle on 39 minutes when Shaun Doherty fed Nigel McMonagle who managed to lob the ball past Jack Nelson in the Carn goal to the top cornier of the net.
Carn pulled one back on 41 minutes after Shane Doherty released Girts Dzerins on the right wing and he crossed for Cade Cooke who headed it past Dylan Doherty .
Carn nearly got another one back 5 minutes after the restart when a Michael McDermott pass from midfield found Christy McDaid who made a great run and slotted it to Dermot Doherty but he fired narrowly wide from 15 yards.
Greencastle got their fourth on 65 minutes after David Henry was upended in the penalty area and Jamie McCormick converted the resulting penalty.
Greencastle made it five on 75 minutes when Matthew Henry broke on the left wing and rounded the defender and squared it for Christy Hegarty who drove it to the bottom right corner of the net from 15 yards.
Greencastle rounded off their scoring on 84 minutes when a Michael Henry pass from midfield found Christy Hegarty who laid it off for Michael Henry who shot low to the right corner of the net from 10 yards.