They then found themselves unable to defend it, as Rob Nicol produced a superb century, reaching it with a swept four off impressive spinner Ronnie Hira in the final over to reach 205 for three.
So does this make Canterbury final favourites? No, but it was a strong indicator that Sunday's decider should be a cracking contest.
It was Auckland's second defeat in the round-robin but Canterbury, who lost on the last ball to Auckland at Rangiora a couple of weeks ago, will arrive on Sunday feeling pretty good about their prospects of toppling the defending champions.
Mahmood and Nicol's tons were the third and fourth of the cup joining Mahmood's teammate Martin Guptill and Wellington's Zimbabwean import Brendan Taylor.
Mahmood's was a mix of bludgeoning shots with moments of pacing himself and took him 61 balls, with 10 fours and three sixes, reaching it on the final delivery of the innings.
Nicol's was a terrific exhibition, demonstrating Colin Maiden Park is not big enough to contain batsmen with a giant sweet spot in their bats. Nine of Canterbury's 14 sixes were his - there were 23 in the game - and Nicol compiled his runs from 57 balls.
For a time it looked as if Auckland might not have kept the foot down hard enough to reach 200 after a rollicking start, and Mahmood might be left short of his century.
Guptill has been Auckland's batting hero of the campaign, but he was gone in the second over and in a sense, that was no bad thing for Auckland. For all Guptill's brilliance in the cup, Auckland needed a workout without the runaway leading runscorer.
Gareth Hopkins and Colin de Grandhomme made snappy contributions and at halftime it seemed the challenge might be beyond the Canterbury Wizards.
However, openers George Worker and Rob Nicol didn't mess about as the light faded on a cool, gloomy evening.
Once Dean Brownlie joined Nicol in a 68-run stand off 38 balls it was left to Nicol and Brendon Diamanti to finish the job. Roll on Sunday.