Hawks forward Hyrum Harris willed his team back into the contest with five offensive rebounds over a first half in which he led the Hawks with 15 points.
They would have been relatively pleased to go into halftime down just 47-41, particularly given their poor start and low efficiency and volume of three-point shooting (2 of 8 in the first half).
Semifinal hero Devondrick Walker hit the only two baskets in the first five minutes of the second half and the Hawks drew level as the game became a defensive arm-wrestle.
He continued to hit shot after shot, and with Derone Raukawa and Harris beginning to find some joy driving to the basket, the Hawks took a four-point lead into the fourth quarter.
The lead was traded back and forth constantly as the game approached the final stretch, with the two best teams in the country going basket-for-basket against equally focused defensive effort.
Samuel hit a massive three-pointer with just over two minutes left to give Wellington a two-possession lead.
The Hawks caught an unlucky break with 27 seconds left when the referees missed an out of bounds call on Wellington star Dion Prewster with the Saints winning 77-75.
Hawke's Bay did get the ball back for a final shot to tie or win, but Walker's contested shot at the buzzer fell well short.
"It was just a couple plays that we didn't make that we needed to, that's the game," the Texan said afterwards.
Kerwin Roach Jr (16 pts, 7 rebs, 3 ast) was rightly crowned MVP of the game for a brilliant performance on both ends of the court.
It was a heartbreaking end to a fantastic season for the Hawks, who still have just the one national title to show for their eight grand final appearances.
The loss will taste all the more bitter given Wellington have defeated them in their last four trips to the championship game (2011, 2014, 2019, now 2021).