The ASB Premiership champions defeated FC Gaitcha 1-0 in Suva Tuesday to book their place in the decider.
Serbian defender Marko Dordevic headed the only goal midway through the second half of the semifinal.
The result continues an extraordinary run by the Sandringham club, who will be seeking their fifth successive OFC crown in Sunday's final.
Since missing out on the final in the 2009-10 season (Waitakere United advanced instead) Auckland City have been imperious at this level. It hasn't always been plain sailing but the Aucklanders have developed a knack of lifting their game when it matters, to trump Amicale (2011, 6-1 on aggregate), Tefana (2012, 3-1 on aggregate), Waitakere United (2013, 2-1) and Amicale again (2014, 3-2 on aggregate).
No other Oceania club has won more than two successive titles since the current format was put in place in 2005.
Tuesday's match was a battle - Auckland City always looked the more dominant side but a failure to make the most of their chances kept the match in the balance.
The New Zealand side were heavily favoured going into the game; FC Gaitcha were the first side from New Caledonia to progress beyond pool play in this competition since 2005, while Auckland City had never lost in four previous matches against teams from “Le Caillou”.
But the hot, humid conditions and a pitch that had seen 12 matches over the preceding 11 days was always going to be a leveller.
Auckland City's main threat to the opposition came from set piece and it was no surprise to see Dordevic profit from a pinpoint Daewook Kim free kick in the 70th minute. Dordevic had been in the thick of the action - he had a header cleared off the line in the first half, then failed to connect with another aerial chance early in the second half after being left unmarked at the far post.
Jim Ouka went closest for FC Gaitcha when he fired over from the edge of the box after a neat lay off from New Caledonian international Bertrand Kai. Kai, who scored against the All Whites in the 2012 Nations Cup, was the main Gaitcha threat but left the field injured in the second half.
“These one-off games are never easy and FC Gaitchawere pressing us high up the pitch but finally we capitalised on a set piece,” said Auckland City coach Ramon Tribulietx.
“I'm happy with the result, ... in the second half we created a lot of chances,” he said.