Led by their inspirational skipper Ash Dixon and scrumhalf Folau Fakatava, the home side forced Northland into mistakes as the game wore on and were unlucky that two tries were disallowed.
Northland had earlier got off to a flying start, courtesy of a string of early mistakes by Hawke's Bay inside their 22m line, and scored the first try through prop Luatanagi Li who barged over under the sticks.
Hawke's Bay replied three minutes later through wing Jonah Lowe when he gathered a kick in behind the Northland defensive line by Stacey Ili.
Centre Neria Fomai scored the host's second try, before halfback Will Grant levelled the scores after receiving an inside pass from Rene Ranger close to the tryline.
It looked as if Northland would lead at halftime, but wing Lolagi Visinia scored in the corner off a lineout move.
Northland sent in Scott Gregory, Ross Wright, Matt Matich and Kane Jacobson not long after halftime, but Hawke's Bay had too much presence and too much presence of mind.
The Mitre 10 Premiership final between Auckland and Tasman is at Eden Park tomorrow.