Also putting in a strong performance was Wellsford fullback Matt Wright, who stepped up to take on the goal-kicking duties early in the first half after first five Dan Hawkins was sinbinned for slapping down a wide pass from Manawatu.
Wright set up Northland's first try of the season with a spectacular kick return from 40m out as he beat two defenders with footwork and speed before forcing Manawatu to sell the farm on a faked outside pass.
Nakosi was on hand to receive an inside pass and sprint the last 15-odd metres to dot down.
Northland's second try came after 13 phases of attack, that included several pick-and-goes close to the line, that was finished off by Tane Takulua, who drove over and celebrated in style.
Their phase play in the lead up to Takulua's try showed Northland has the ability to play controlled rugby and didn't panic in the build-up as they attacked one side before spreading back to the other.
It would be fair to say, though, there was not enough panic in the Northland defence in the final 10 as Manawatu managed two quick tries, making an otherwise-strong Taniwha defence look average.
In the 74th minute Manawatu captain Callum Gibbons delivered the final blow as he dotted down after a run off the back of a maul that caught Northland's defence napping around the fringes.
After the game Northland captain Cam Eyre said their focus would be on ball security.
He felt his side gave Manawatu too many opportunities, which is reflected in Northland giving away 18 first-half turnovers and having less territory and possession.
"We kept the aggression levels up and we scored some good tries, but they don't get you wins," Eyre said.
"We've got to hold tough for 80 minutes. We just lapsed towards the end and they hurt us.
"It's all well and good throwing the ball around and be entertaining but we've got to close it out and be sensible.
"If you give them 50 chances they'll always win."
Northland had two sets of brothers on the field towards the end as both the Pryor and the Wright siblings were wearing the Cambridge blue.
All in all the Taniwha no doubt will be disappointed with the result but played an attractive brand of football in front of a decent home crowd.
Northland's next game is next Saturday against Wellington at 2.35pm at Toll Stadium.
Manawatu 28 (Antonio Kiri Kiri, Hamish Northcott, Callum Gibbons tries; Jade Te Rure 2 cons; Te Rure 3 pens) Northland 23 (Filipo Nakosi, Tane Takulua tries; Dan Hawkins 2 cons; Matt Wright, Hawkins pens).
