Auckland remain a chance of upsetting table-topping Central Districts in the Plunket Shield but it will take a favourable final day's play at Eden Park's outer oval.
Central Districts batted throughout the third day to overhaul Auckland's advantage and take a lead of their own, leaving all three results possible today.
The Stags, 40 points ahead of the Aces but having played a game more, will begin the final morning with a lead of 271 and four wickets in hand. Auckland will need to quickly wrap up the CD tail before settling in for a challenging chase.
After Jamie How's determined century brought his side back into the match, Kruger van Wyk (31no) and Doug Bracewell (36no) will resume in the middle of the Eden Park No 2 pitch.
The Stags began the day on 107-0, with How and Jeet Raval batting on to establish a record opening partnership. By the time Bruce Martin broke through, the score was on 173 and the Stags were well placed for a big total. How was eventually dismissed for 124, the opener's 15th first class century, which brought Ross Taylor to the crease for another brief stay.
The former New Zealand skipper matched his first innings score of 21 but was caught behind from the bowling of Chris Martin as Auckland struggled to break through the Stag's defences, with the visitors eventually reaching 386-6 at stumps.
Elsewhere, Otago are well-placed to win their clash with Northern Districts and close the gap between themselves and CD at the top of the standings.
After beginning day two on 135-2 in Queenstown, Otago opener Hamish Rutherford celebrated his call-up to the New Zealand side for the limited overs series against England by blasting his fourth first class century.
Rutherford was part of a 149-run stand for the third-wicket, broken when Neil Broom was run out for 42. Rutherford was next man out, dismissed for 162 from just 187 balls, but Otago were already ahead of the Knights' first innings total of 217.
The Volts may have liked a bigger lead than the 102 runs they ended up with, but their bowlers soon rammed home the advantage by taking three wickets and leaving ND on 141-3, with a lead of 39, at stumps.
In Wellington, the hosts' match with Canterbury is evenly poised at the halfway mark after they managed to overhaul the Wizards' first innings score of 329.
A century from Stephen Murdoch (102) was the best for the Firebirds, with the No 3 sharing in a 131-run partnership with Jesse Ryder (78).
Wicketkeeper Luke Ronchi advanced his international prospects with 95 from 99 balls as Wellington were eventually dismissed for 356.
Canterbury's openers were made to survive a tricky 13-over spell before stumps, but Peter Fulton (18no) and George Worker (25no) saw their side safely through to stumps with a lead of 16 runs.