Carl Cachopa compiled 111 batting at No 3, but his stay was ended by discarded Black Cap Brent Arnel. Matt Sinclair made 66 before falling to another unwanted New Zealand quick, Trent Boult, while Kieran Noema-Barnett ended the innings unbeaten on 105.
Graeme Aldridge was the best of the ND bowlers with 4-74, while Boult picked up three wickets and Arnel two.
The Knights' success left Auckland needing something of a miracle to rise from their second place to claim the prize. Only a huge helping hand from Central Districts - first to restrict Northern to fewer than 300 in the first innings, then to win or draw the match - will give Auckland a chance.
And for that chance to come to fruition, Auckland will still need to acquire all 20 available points, something they made a good start toward achieving on the first day against Canterbury.
In Dunedin, Wellington's faint hopes of claiming the title were quickly extinguished thanks to Neil Wagner.
The South African-born quick, who becomes eligible for New Zealand within the fortnight, took an outstanding 7-46 in bowling out the hosts for 112. APNZ