Cookstown hosted Mossley on Monday night knowing a win would secure third place in the Premier League.
They also welcomed back previous coach Fergie Cosgrove and player Alan Mullan.
In the opening encounters both teams had chances to break the deadlock but both keepers made quality saves. The longer the half continued it looked like Mossley would be the team to break the deadlock but against the run of play Raymond Miller turned well in the circle and slapped home past McMillan in the Mossley goals.
Cookstown were glad half of half time giving them an opportunity to regroup and address some areas for attention.
After the break Cookstown extended their lead through Andrew Barbour, he found himself high up the pitch on the right hand side and he rolled back the years to show the Cookstown faithful that he still has the turn of pace to beat a defender with ease before unleashing a well placed shot backboard high into the right hand side of the goal.
A third was soon added when Ryan Millar got his name on the scoresheet when he followed up well on an Allen initial shot. Gareth Cuddy made it four in similar fashion when he slapped home from close range, a fitting way for the number five to finish his Premier League career.
Keith Black had the opportunity to make it five from the penalty spot but McMillan pulled off a fantastic save.
Mossley did get a deserved goal back with three minutes left when McWhirter was unfortunate to put the ball past Hughes into his own net.
Cookstown will be pleased that the three wins in a row secured them 39 points and third place, the same tally that won the league two years ago.