Northland No2 Peter Bone was the hero for the Taniwha. He was four down to John Warrington at one stage but came back to win 2 and 1 in what was the crucial point for Northland.
The home team then went on to thrash Poverty Bay (5-0) in the afternoon to leapfrog Auckland (3 wins, 10.5 individual points) and Canterbury (3 wins, 11 individual points) into top spot with three wins and 12 individual points.
Hopes are rising among their supporters that Northland can maintain momentum to claim a famous Diners Club Freyberg Masters win on home soil.
Meanwhile, Auckland kept their chances alive with a gutsy display in the morning session.
The Blue and Whites defeated one of the favourites, Aorangi, by 3-2 in what could also prove a decisive contest. They always had the edge in the close battle as they kept their perfect winning record alive after three matches.
Auckland, the most successful team in the history of the event, are looking for their first win in championship since they won at the Lochiel Golf Club in 2003.
Auckland, Northland and Canterbury are the only teams to have won three from three matches after four rounds.
The Freyberg Masters is a unique round-robin format in which teams play eight of the 14 districts, with the team who gather the most points crowned the champion on Friday afternoon.
The golfers are aged 40 years and over and are playing for the right to be called national champions of their age group.
There is still a long way to go but at the end of day two, three teams have a slight advantage heading into the business end of the tournament.
Freyberg Masters
Bay of Plenty 4 Poverty Bay East Coast 1: Blair Murdock bt Dougal Watts 5/4, Justin Rasmussen bt Simon Jeune 3/1, Mikki Strong lost to John Wyllie 1down, Steve Heberley bt Bruce Yates 2/1, Bryan Prani bt Tene Goldsmith 5/4
Bay of Plenty 2.5 North Harbour 2.5: Blair Murdock halved with Mike Leeper, Justin Rasmussen bt Rob Simmonds 3/2, Mikki Strong lost to Rob Noffke 3/2, Steve Heberley bt Stuart Nicholls 3/2, Jason Madden lost to Mark Dawson 1down.