Plagued by inaccuracies all around the paddock, Otago led 20-15 at halftime but could only score a sole penalty in the second half while Northland scored 25 points.
Otago failed to get anything going on attack and was outmuscled in the breakdown
It was not a great dress rehearsal for Otago which has a Ranfurly Shield challenge in four days.
Northland 40 (Jack Ram 2, Namatahio Waa, Ross Wright, Matt Moulds tries; Dan Hawkins 3 con, 3 pen) Otago 23 (Tom Franklin, Hayden Parker tries;Parker 2 con, 2 pen; Peter Breen pen) Halftime: 20-15 Otago