Plunket Shield leaders Central Stags are chasing 267 runs for a first-innings lead over Northern Knights at Nelson.
Having dismissed their rivals on the opening day of the final round, the Stags are 46 without loss at stumps.
Daryl Mitchell led the Northern scoring with 72 runs and combined with wicketkeeper Cameron Fletcher (34) for an 87-run stand that formed the backbone of the innings.
After retiring hurt, James Marshall returned to chip in 54 runs, but the Knights lost their last three wickets without adding to their score. Ben Wheeler had two of those victims among his 3-35.
At the end of day's play, Jeet Raval was unbeaten on 27 and Jamie How was 17 not out for Central.
Meanwhile, the Stags' closest rivals - Otago Volts - are 113-2 in pursuit of 255 against Wellington Firebirds.
Opener Michael Papps top-scored for the home team with 63, while Jimmy Neesham took 3-39 for Otago.
In response, Aaron Redmond was unbeaten on 60, after sharing a 72-run stand with Michael Bracewell (33).
Meanwhile, Shannon Stewart's maiden first-class "five-for" had Canterbury Wizards in a dominant position against the Auckland Aces.
Stewart narrowly missed a hat-trick, taking three wickets in a maiden over, and his 5-42 helped dismiss the Aces for 173, with Anaru Kitchen (41) top-scoring.
At stumps, Canterbury were 128-1, with Peter Fulton unbeaten on 80.