Bates has a well-deserved reputation as a quality domestic death bowler and used cross-seam guile and pace variation to have Kuggeleijn caught at deep square leg, Boult caught at long on, and Sodhi caught behind.
Bates couldn't have picked a better time to deliver. With a place in the final on the line, and the prospect of Champions League riches for the eventual competition winner, there was everything to play for.
Northern got off to a flier thanks largely to Irish import Kevin O'Brien, who hit an imperious 52 of 25 balls. He bashed his side to 101-4 after 12.2 overs and his innings had some sublime moments - a six over extra cover off a short-pitched ball almost defying plausibility.
At that point Auckland were facing the the prospect of a daunting run chase, but once Irishman fell to leg-spinner Tarun Nethula, the brakes were applied thanks to the miserly trio of Bates (4-10), Nethula (2-20) and Donovan Grobbelaar (1-26).
Needing only seven an over, Auckland went about their work in business-like fashion and never looked like losing.
Craig Cachopa led the way with an unbeaten 79 off 47 balls, receiving solid assistance from Rob Nicol (19 off 20) and Colin Munro (28 off 19).