The Volts were set the unlikely target of 553 for victory when Canterbury declared its second innings at 350 for two.
The mammoth task of saving the game grew another set of tusks when centurion Brad Wilson was trapped lbw in the last over of the day.
Otago will resume day four on 213 for six and trails by 340 runs.
The visiting side is effectively seven down after Sean Eathorne, playing his first four-day game for the province in nine years, was forced to retire hurt when he was struck in the back of the shoulders by a bouncer from Logan van Beek.
Canterbury resumed yesterday on 272 for two with a lead of 474.
Veteran top-order batsman Peter Fulton, on 97 overnight, brought up his 18th first-class century and 15th for Canterbury.
His hundred came up off 115 balls.
Once he reached the milestone, he played with even more freedom, taking just 24 balls to add another 50.
When Fulton declared, he was undefeated on 155 and Ken McClure, who had posted his maiden first-class 50, was also unbeaten on 66.
The pair's unbroken stand of 218 eclipsed the previous Canterbury third-wicket record against Otago of 178 scored by Robbie Frew and Michael Papps in 2000-01.
Nick Beard was the only Otago bowler to pick up a wicket in Canterbury's second innings.
The left-arm spinner took two for 92 from 19 overs.
Albion allrounder Roald Badenhorst was the most expensive of the bowlers.
His six overs cost his team 61 runs but all the bowlers took some punishment.
Otago made a steady reply, getting through to 50 before Ryan Duffy was caught behind.
The big breakthrough came when van Beek trapped Neil Broom lbw for 22.
Broom is arguably the best equipped of the Otago batsmen to occupy the crease for long periods.
That said, Wilson was doing a marvellous job holding up one end.
The opener played a key role in helping Otago hold on for a draw against Central Districts in round one and was once again defiant.
He posted his ninth first-class hundred and first for Otago and spend more than five hours at the crease.
• There was a dramatic finish in Nelson with Wellington securing a five-wicket victory against Central Districts with just over two overs to spare.
Tom Blundell hit an undefeated 77 from 88 balls to guide his side to the win.
He had wonderful support from Luke Woodcock (31 from 19) and Michael Pollard (65 from 88).
Earlier, Central Districts had declared its second innings closed at 273 for eight, setting Wellington a target of 306 for victory. Ben Smith starred with 117, his fourth first-class 100.
