Central Districts' top three all scored hundreds during the opening two days of the fixture at McLean Park.
That left the Volts chasing a mammoth first innings total of 584 for eight declared.
Otago folded for 244 and was promptly asked to follow on. The visitors have offered stiffer resistance in their second dig.
Openers Hamish Rutherford (63 not out) and Camden Hawkins (52) put on 111 for the first wicket, and at stumps Otago was 124 for one.
It trails by 216, so there is still an enormous rescue job ahead. The Volts have lost their last six first-class games and will be desperate to snap the streak and escape Napier with a draw.
Central resumed on Saturday at 357 for one with Greg Hay undefeated on 145 and Will Young closing in on his seventh first-class century.
Hay added 13 runs to his overnight score before he was undone. Jacob Duffy found the edge of his bat and rookie gloveman Max Chu took his first catch for Otago.
Young powered his way to 150 and Dane Cleaver whacked 83 from 81 balls.
Central declared about an hour before the tea break, 16 runs shy of 600.
Michael Rippon snapped up some late wickets but he will not remember his four for 174 with any great fondness. Matt Bacon and Duffy also went for more than 100 runs.
Otago needed to start well but paceman Blair Tickner (four for 25) removed both openers before they could cash in on promising starts.
Hawkins (29) played around a straight delivery, while Rutherford (30) was surprised by a ball which bounce a bit more and took the splice of the bat.
The home side took another step towards victory when Josh Finnie (10) went early yesterday morning. Tickner got him with a rising delivery which brushed his gloves on the way through to the keeper.
Nathan Smith (45) and Matt Bacon (43) put on 72 for the ninth wicket.
But Doug Bracewell (three for 41) wrapped up the innings with a tremendous ball which nipped back and bowled Smith.
In Whangarei, Auckland is 31 for none in its second innings and leads Northern Districts by 123 runs with a day to play.
In the other match, Wellington is 153 for six in its second innings. It needs a further 22 runs to make Canterbury bat again after being forced to follow on.
Canterbury's Matt Henry has eight wickets in the match, while Cole McConchie stroked 162 to help set up a strong position for the home team.
