The left-hander swung away four sixes in the final two overs and almost did the unthinkable.
He smashed 50 from 28 deliveries, leaving Otago needing just three runs from the last ball to steal an unlikely victory. With two overs remaining, Otago required 36 from 12 deliveries and Wells let fly. The target came down to 18 off six balls.
Former Black Cap and Wellington left-armer Andy McKay watched helplessly as the fourth and fifth ball of the last over sailed over the ropes at the Basin Reserve.
But despair turned to joy when Wells just did not get enough meat behind his final shot. Grant Elliott took the catch to complete a dramatic two-run win.
It was perhaps fitting he took the catch. Earlier, he hit the stumps to run out Aaron Redmond for 96 and then Brent Arnel trapped Jesse Ryder lbw the very next ball.
As far as a turning point goes, that was a U-turn. Wellington had posted an impressive tally of 308 for five and Otago needed all the luck it could get.
The Volts had actually been progressing nicely.
Redmond and Michael Bracewell (60) set the platform, adding an Otago record 155 runs for the second wicket. The pair eclipsed the previous mark of 134 unbeaten scored by Mark Richardson and Michael Lamont against Auckland in 1998-99.
Arnel got the breakthrough when Bracewell holed out at mid off. The veteran seamer bowled superbly to take two for 37 from 10 overs.
While Otago had Ryan ten Doeschate at the wicket, there was still hope. However, the Dutch international succumbed to scoreboard pressure, offering a catch on 34.
Wellington made a fantastic start as Michael Papps and Stephen Murdoch put on 144 for the first wicket.
The pair got the home side on course for a chunky total but Otago rallied.
Murdoch offered a catch on 89 and then veteran left-armer Bradley Scott took two wickets in one over. He bowled Elliott for 28 and Matt Taylor of four.
Spinner Mark Craig prevented Papps adding to his 12 one-day centuries, nicking him out on 98.
The prospects of posting 300-plus appeared to be slipping away but 23-year-old rookie Tom Blundell smashed 47 from 31 and captain James Franklin added 24 not out from 16.
Scott was perhaps the best of the Otago bowlers with two for 47 from nine overs.
The normally frugal Nick Beard was expensive with none for 61 from nine and Wells got clobbered, conceding 58 from eight. He did pick up the wicket of Murdoch, though.
The loss has left Otago at the bottom of the Ford Trophy competition table with two losses from three games.
The Volts will return to Dunedin where they will host Canterbury on Wednesday and look to get revenge against Wellington on Sunday. Those fixtures shape as critical for Otago's prospects of making the playoffs.
In other matches, Canterbury had a 10-wicket win - yes, 10 wickets - against Central Districts. Central was dismissed for just 94 in 19.1 overs at Hagley Oval.
Andrew Ellis took five for 17 and Hamish Bennett three for 29. Canterbury openers George Worker (46 from 38) and Tom Latham (50 from 54) needed just 15.2 overs to seal the win.
Northern Districts also had a big win. The Knights posted 257 for five as BJ Watling top-scored with an undefeated innings of 97. He had good support from Daryl Mitchell (59) and Jono Hickey (32).
Auckland slumped to be all out for 147. Donovan Grobbelaar top-scored with 29. The wickets were shared around.
