The second half saw the teams trade tries, then with less than 10 minutes to go Ngatapa took the lead when prop James Higgins made a breakaway down the blindside.
He bumped off several tackle attempts on his way to scoring in the corner, to give his team a three-point lead.
With less than three minutes on the clock OBM regained possession through a lineout on halfway before making their way up the field through a series of strong runs and penalties.
OBM slowly made their way to within five metres of the tryline before a series of penalties for infringements in the maul, Terekia was able to find his way over the line as the whole OBM team including the backline piled into the final play of the game.
Ngatapa manager Steve Craill said the game was a treat for the dedicated supporters who braved the weather.
“Both teams played with 100 percent guts and determination . . . it was a good advertisement for club rugby.”
He said it was unfortunate that they couldn't hold onto the lead at the death but the team should be proud of how they performed.
“We know we'd been under-performing in the first round. We wanted to address that and I think we did.
“I think we're heading in the right direction . . . we're definitely capable of pulling out the big game in the business end.
“They did the jersey proud.”
He said the effort from the forward pack was monumental, with Higgins looking like a back during his run down the sideline after playing over an hour of rugby already.
In the backs, Nash Mouton was “very busy” on attack and did a “ton of work” on defence, Craill said.
OBM coach Clint Pirihi said he was proud of how his team dug in to stay in the fight when the going got tough.
“I'm proud of the boys showing heart, passion and proving when it comes down to it, we can do it.”
His team was performing well in the first half, but their control of the game slipped in the second, he said.
“I don't know what happened. They made some changes, the momentum changed and they (Ngatapa) took advantage of that.
“We tried to play running rugby as much as we could. It took us a while to realise that it wasn't working and to keep it in the forwards.”
Pirihi said he was very proud of how his forwards responded to the pressure, led from the front by Terekia.
“Morgan Reedy also led from the front. So did Lance Dickson, doing the jobs that needed to be done.”