Northland's reply was equally as lucky when a skewed kick from first-five Daniel Hawkins led to a dodgy bounce and when flanker Dan Pryor snatched the loose ball and offered a deft pass to wing Whiria Meltzer, the No 14 did the rest and blazed down the touchline to score.
Meltzer's strike came right on halftime, which gave the visitors an 11-7 lead heading in to the break.
Manawatu pivot Jade Te Rure helped erode the deficit with an early second-half penalty before Bedwell-Curtis completed his brace with a try from close-range in the 63rd minute, which gave the Turbos a lead they would never cough up.
A 75th-minute Lewis Marshall try iced the win, although Northland did manage a late score through Derek Carpenter to grab a bonus point.
Manawatu finish their regular season against the high-flying Tasman in Blenheim next Sunday.
Manawatu 22 (Heiden Bedwell-Curtis 2, Lewis Marshall tries; Jade Te Rure pen, 2 con)
Northland 16 (Whiria Meltzer, Derek Carpenter tries; Daniel Hawkins 2 pen) HT: 7-11