Northern posted 410 for nine to overhaul Otago's total of 305 and grab first innings points.
When play ended, Otago had reached 115 for two in its second innings.
With Canterbury and Wellington both picking up outright victories, Otago will need at least two outrights in its remaining three matches to make the final.
Otago coach Mike Hesson described it as a frustrating game. Otago had hoped Northern would declare once it got first innings points to set up an exciting finish. But by batting on and building a lead of 105 runs the game effectively ended as a contest.
‘‘We tried to get the game to open up but unfortunately Northern Districts did not want to set up a game, which was a shame,'' Hesson said.
Rain did not help the contest either. The morning session was washed out yesterday, which left Otago with little more to gain than some batting practice.
There were some positives for Otago. Captain Craig Cumming batted well in tricky conditions at the start of the match and Aaron Redmond dug in during the second innings.
Opener Brad Wilson anchored Northern's innings with a maiden first-class 100. The 22-year-old right-hander occupied the crease for more than six hours to bring up his milestone, but was promptly dismissed when he offered Redmond a catch off the bowling of Craig Smith.
Northern's middle order of James Marshall (67), Daniel Flynn (46) and Peter McGlashan (69) all chipped in to secure first innings points.
Otago left-arm seamer Bradley Scott bowled well without luck. His 25-over spell included nine maidens and cost just 43 runs.
Fellow lefty Smith also bowled well with two for 42 from 19 overs, and Warren McSkimming and Nathan McCullum picked up two wickets apiece.
Cumming had a muscle strain and, as a precaution, did not take his place at the top of the order for Otago's reply. He could have batted if required and is expected to be fit for Otago's match against Wellington at the University Oval this week.
Redmond, though, settled in for a long stay at the crease. His 41 runs came off 202 balls and he had good support from Jordan Sheed (34).
Otago has the day off today and will assemble for its crucial match against Wellington tomorrow.
