The Volts must be starting to wonder when their charmed run will come to an end. They have certainly been the most consistent side in the tournament and had already secured a home venue for Sunday's final. But even the best side in the competition needs a little luck every now and then and Otago got it during the last over.
Chasing Canterbury's total of 162 for six, Otago needed eight to win from the final over.
Bowler Logan van Beek released the pressure valve with a wide and Ian Butler found an inside edge to reduce the equation to two from two. But he nicked out, leaving off-spinner Mark Craig to finish off.
Canterbury brought the field in to cut off the single and force Craig to go over the top. The left-hander had a heave and got lucky, slicing a thick edge down to the vacant third man boundary.
Otago now needs its luck to hold out for one more match. Auckland beat Central Districts by six wickets with help from the Duckworth-Lewis method and will play Wellington in the preliminary final in the capital on Friday. The winner will travel to Dunedin to met Otago in the final.
Wellington has largely been powered by big-hitting Jesse Ryder, while Auckland looks to have more firepower across the board. But Otago has beaten both sides twice this year and coach Vaughn Johnson is not too concerned which team makes it through.
''I don't really care who we play,'' Johnson said.
''Whoever wins [the preliminary final], straight after that game they have to travel to Dunedin, so it is going to be pretty tough.
''You've got to be confident but you've also got to understand twenty/20 is a pretty fickle game. You saw that tonight. We had the game under control and then it came down to the last ball.''
Otago bowled well, except for Ryan ten Doeschate who conceded 31 runs from two overs. Former Australian fast bowler Brett Lee was flown in for the match and gave excellent service. He bowled with plenty of heat, took one for 19 and effected a fantastic run out. Eighteen-year-old Jacob Duffy was once again superb at the death, and left-arm spinner Nick Beard took three for 26 from four overs.
Canterbury openers George Worker (58 from 44) and Brad Cachopa (37 from 28) set a good platform but the visiting side was not able to build on that start.
Otago made a sluggish start to its reply but Aaron Redmond generated momentum with a brutal 21-ball half-century. Hewhacked three huge sixes and got the chase back on track.
However, his departure saw Otago start to play a bit too safe. Ten Doeschate seemed to be pacing the innings but holed out in the 19th over for 30, chipping a full toss to midwicket.
The delivery, though, was a very good disguise for a waist-high no-ball. Ten Doeschate hung around waiting for the square leg umpire to issue him a reprieve but the pardon never came. Butler hit the last ball of the penultimate over for six and that proved a crucial blow. Craig and the thick edge of his bat did the rest.
Andrew Ellis was easily the pick of the Canterbury bowlers. He bowled a rare wicket-maiden and finished the match with two for 14 from four overs.
Otago will take a day off today before reassembling early tomorrow morning to begin the preparation for Sunday's final.
