Neither team caved during the final quarter, with a number of penalty corners and shots being saved by both McGrail and Bay 2 goalkeeper Logan Geary.
The shootout was as intense as the fourth quarter, with neither team able to pull ahead, ending in a sudden-death scenario.
Sixteen-year-old McGrail denied veteran McAleese's initial attempt and defended his goal for the full eight seconds - securing the victory for his team.
McAleese said it was fitting that McGrail won the game for Bay 1 in the shootout after a great performance throughout a very even match.
"Their player of the game was Jack, the goalie," he said,
"In the game he saved five or six shots that were just like 'woah'. He's a proper good goalkeeper and showed his worth in the shootout as well."
Reflecting on the season for both Bay Independent sides, McAleese said it was the right decision to split their squad into two teams.
McAleese added: "When you draw and it goes to a shootout, that's a reflection of how even the teams are - which is what we were trying to achieve."
As star of the show, McGrail put his title-winning performance down to pure confidence in the shootout. He was playing through the pain after having a nerve-root block injection in his back just two days prior to the final.
"I knew they had three class players, three New Zealand reps and I thought 'it's okay if they score, but I've got to save at least two'," he said.
"It was great to get one up over Shea, who has a few hundred caps for New Zealand now. That always feels good."
Bay 1 player-coach Charles Jenkins said the young goalie's impact on the game was incredible, especially after medical treatment just days before.
"We would've lost without a performance like that," Jenkins said