After winning the toss and electing to bat, Auckland were left defending a less-than-impressive 197 from 49.1 overs at the Basin Reserve.
They came closer than expected, thanks mainly to Tuffey's sterling work early on into a strength-sapping north-westerly, but the State Wellington Firebirds picked a four-wicket win with just under two overs to spare.
Wellington had the Aucklanders looking shaky at 14 for two, before captain Richard Jones and newcomer Anaru Kitchen put on 85 for the third wicket.
Jones was dismissed for 39 with the score on 99, Reece Young disappearing two balls later without adding to the score, trapped leg before wicket by the left arm othodox spin of Luke Woodcock.
Woodcock eventually picked 3-27 off eight overs, with Graeme Napier's 4-40 off 10 the pick of the bowling.
Kitchen's 65 off 93 balls, backed up by English import Steve Croft's 39, gave Auckland a barely respectable total to defend, but Tuffey gave them the best possible start with three wickets inside the opening seven overs.
The former Black Cap picked up the invaluable wicket of Wellington captain Matthew Bell, who lasted only five balls before he was dismissed without scoring by a superb diving catch from Martin Guptill at cover point.
Wellington were left reeling nine balls later when Neil Parlane was caught behind by Gareth Hopkins, again off the bowling of Tuffey, with the total on three.
Tuffey struck for a third time at the end of the sixth over, Hopkins taking another tidy catch behind the stumps to dismiss Stephen Murdoch for eight.
That brought together BJ Crook and James Franklin, who put on 98 for the fourth wicket before Franklin departed, caught behind off Tuffey for 38.
Crook went on to anchor the innings, his 75 coming of 136 balls before he was cleaned bowled by Paul Hitchcock in the 41st over. However, Chris Nevin (52) saw Wellington through, his half century coming with a match-winning four in the 49th over.