A tied score at the half was enough to motivate the Taniwha as they dominated the first stanza of the second half. However, a wealth of possession only resulted in seven points and Southland capitalised on staunch defense, scoring three tries in 10 minutes.
That gave them a 20 point lead which they were able to defend through the final 15 minutes.
James Schrader's double and Wharenui Hawera's backline leadership showed just how potent the young Southland attack can be.
The bonus point win should have lifted Southland back above Northland in the Championship standings, however a last minute try to Jone Macilai ensured the Taniwha took away two bonus points and therefore stay ahead of the Stags on points differential.
Southland 39 (J. Schrader 2, M. Molloy, W. Hawera, T. Tuimavave tries; W. Hawera 2 cons, pen, J. Cowan DG, G. Dyer 2 cons)
Northland 31 (P. Kite, P. Breen, S. Neville, A. Stokes, J. Macilai tries; P. Breen 3 cons)
HT: 12-12