However the impending rain signalled a change in momentum for Moerewa as they found their groove with ball in hand, scoring 32 points in 19 minutes.
Captain and second rower Eli George fought his way over the line with two defenders draped over him to get them on the board.
Shortly afterwards centre Wilson Hona went on a cross-field run before finding a hard-running Brodee Palmer for a four-pointer.
Halfback Palmer was on the score sheet again soon after as fullback and man-of-the-match Jaydenn Bentley-Hape found space and linked with the half to put them up 16-8.
They weren't done yet. Impressive centre Te Tuhi Tipene continued his 2017 try-scoring exploits as he found open space down the sideline while winger Jahdon Palmer added one of his own on the other touch line.
A mistake from the kickoff by Takahiwai gave Moerewa the chance to add the icing to the cake as Peter Prime found space and cruised over to give Moerewa the 32-8 halftime lead.
Takahiwai needed a fast start to the second stanza to stage a comeback and things looked up for them less than 10 minutes into the last 40 of the season.
Halfback Jesse Epiha provided that as he put captain Ross McFarlane in a gap to score.
They needed another quick effort to be right in the contest but Moerewa held strong to make the equation a lot tougher.
Takahiwai reduced the gap to 16 when Epiha dropped the ball off to prop Nick Schuster who produced a massive fend en route to the try line.
But Moerewa hadn't forged a reputation of being the premier attacking side in Northland for nothing.
They clinically worked their way downfield before finding Jahdon Palmer for his second try.
Takahiwai scored shortly afterwards through winger Joel Suvalko but going tit for tat wasn't going to be enough.
Moerewa scored once again through Prime with six minutes to go, sparking the beginning of huge celebrations from the Moerewa faithful.
Hool scored a consolation try for Takahiwai after the siren but the result was beyond doubt. Moerewa were the champions.
George said it was a great way to recognise Moerewa's 50th year as a club.
"We started slowly but we picked our game up. Our preparation was great and it showed out on the field," he said.
"It's been a long time since we've won. Ten years on the trot we hadn't done it so to do it on our 50-year anniversary is pretty cool."