The year 13 Sacred Heart College pupil wasn't in the losing Neil Emblen-coached side last year although 90 per cent of the team were still the same.
Western Springs had found themselves 1-0 down in some of the previous seven games leading to the final so Imrie said they had the character and resolve to bounce back from any adversity.
"I was just working hard. I went down and didn't get it but I didn't give up because I knew my boys would give me another chance so I'm ecstatic."
Imrie's winner was deposited into the back of the net after a teammate lobbed it back into an 18m-box following some lackadaisical attempts from Birkenhead to repel waves of attack from a crowded stock exchange.
It was Western Springs who drew first blood in the sixth minute through a deft shot from pint-sized striker Oscar Browne which curled past a diving Birkenhead goalkeeper, Jack McQuoid, to thud into the back of the next.
That stung the defending champions into action with midfielder Dan Edwards making their intentions clear just two minutes later when he rifled in a shot past goalkeeper Elliott Munford to make it 1-1 for a scoreline that remained into halftime.
In the second spell both sides created opportunities but failed to turn them into goals although there was a hint that Western Springs' defenders were becoming a little lethargic and giving away silly fouls.
A circumspect Emblen, not wanting to get carried away and respectful of Hobson's hard work ethics, said the success was a progression of boys maturing from last year.
"It was tough for my boys because we got relegated in our league from premiership to senior grade," he said, mindful they were young but richer for having entered the elite men's league.
"Those young players gained a lot of experience, as they do at Birkenhead, and that today held us in good stead ... because I think we were more ready for the challenge today than we were last year."
Emblen lauded his defenders - NZ U20 centre back Reece Cox and Liam Williams, who he considers to be very close to making the national grades - labelling them man mountains on the park.
Browne, 15, who he started today, was a "huge prospect" who deserved his selection and repaid that with a fantastic goal.
Imrie, he said, was a 90-plus player who never gave up despite the odds and his relentless attitude would see him find the net with consistency.
"As much as it is painful for us to know we'll be playing in a lower men's league next season I know we have enough young talent who will make the most of those chances.
"Back home, Paul and I speak loads so I have a lot of respect for him and his brief at the club so we're going to be humble with this victory because of the way they are," he said, simply happy just to throw that monkey off the back.
A despondent Hobson said the maiden treble of titles was a major motivation.
"I thought we would do it because I quite fancied the second half but they scored a good goal so I have no complaints.
"They have a great set of players and a good coach so if you want to lose to someone then it's to lose to them."
Hobson said they had lost a few strikers to injury and that might have made a difference.
"It's a great tournament and I always try to come back," he said, adding they had a tough one this year after losing their second game in pool stages.
In the semifinals in the morning, defending champions Birkenhead overwhelmed Bay Olympic 4-1 while Western Springs pipped Glenfield Rovers 1-0 in an all-Auckland club affair.
In the satellite final, striker Max Mata was the toast of Onehunga with a hat trick in the 11th, 37th and 58th minutes to seal a victory against Melville United who got a solitary goal from Mark Glenister in the 44th minute for a 3-1 result in a clean and entertaining affair.
A Melville defender was sent off and a penalty kick awarded to Mata in the dying minutes for his hat trick in what was deemed to be a professional foul on a scoring opportunity.
Melville slayed the Marty Akers-coached Napier Marist 2-0 in their semifinal, dashing any hopes of two Bay flagbearers in next year's tourney, while Onehunga edged out FC Twenty XI 2-1.
The effects of seven other 25 to 30-minute games over three days were visible in both finals.
Onehunga and Melville were both assured main draw berths before their final kicked off.