The Magpies opened the scoring with a penalty to first five-eighth Ihaia West in the third minute. Two minutes later his Taniwha counterpart Dan Hawkins had a penalty attempt bounce off the upright but he was on target in the seventh minute to tie the score.
Numerous turnovers were a feature of the remainder of the first quarter, the bulk of them caused by the greasy ball. Northland also secured two lineouts against the throw during this period.
Hawke's Bay captain and openside flanker Brendon O'Connor scored the first try of the match in the 29th minute. It was his fourth of the season and like his two the previous week in Pukekohe it came off a lineout drive.
West missed the conversion, but three minutes later succeeded with a penalty to give the Magpies an 11-3 lead. A Hawkins penalty in the 37th minute had Northland trailing 11-6 at halftime.
The Magpies were unlucky not to have their second try in the 38th minute when halfback Chris Eaton was forced into touch after collecting a well executed kick from West in a planned move.
Considering the atrocious conditions West's execution couldn't be faulted. Earlier in the half he did one for winger Ryan Tongia to collect which was almost as spectacular.
The Magpies conceded seven penalties in the first half, two more than Northland. While the Magpies had 53 per cent of the possession in the first half, they only had 35 per cent of the territory.
The torrential rain got heavier in the third quarter, but West was again spot on with a kick for Tongia in the 43rd minute. However Tongia was unlucky to lose control when over the line.
Tongia made no mistake four minutes later when he grabbed his fourth try of the season after Northland halfback Tane Tukulua failed to secure a bomb from Magpies fullback Richard Buckman. West added the conversion and the visitors led 18-6.
Northland fought back in the 57th minute with Pryor's try after he won the chase after charging down a kick from Eaton. Hawkins succeeded with the conversions and a 60th minute penalty to have the Taniwha trailing 18-16.
Northland snatched the victory in the final minute when replacement forward Michael Stolberg scored from a penalty tap to tie the score and Hawkins succeeded with the matchwinning conversion from wide out.
West will be disappointed with his two misses at goal. However, it's better for the Magpies to lose this match than next Sunday's Ranfurly Shield defence against Otago at McLean Park.
The Magpies Canadian prop Jason Marshall and Hurricanes prop Brendon Edmonds both had massive workrates. Lock Tom Parsons can be proud of his contribution in his first starting XV appearance of the season.
The Taniwha victory prevented the Magpies from going to the top of the table and it wasn't the result the Magpies wanted for teammate Trent Boswell-Wakefield who missed the match. Yesterday he was attending the funeral for his mother Carole who was killed on Monday when hit by a train while walking her dog in Napier.