Jean-Pierre Bob evaded two challenges before unleashing a stunning right foot shot from 30 metres that dipped under Tamati Williams' crossbar a minute into the second half.
It remained one way traffic from there with substitute Exposito grabbing a treble before Mont Dore's Romain Painbeni had the last say with a left volley with nine minutes from time to round off the bizarre 12-2 score line.
The win was Auckland City's biggest in continental competition eclipsing their 9-1 win over Nokia Eagles in 2006, and their 8-1 hammering of Port Vila Sharks in 2008.
The record winning margin for an Oceania club match is jointly held by Central United and Australian side Wollongong Wolves who both notched 16-0 wins over Tonga's Lotoa'apai in 1999 and 2000.
In recent seasons, Waitakere United thrashed last season's finalists AS Tefana 10-0 at Fred Taylor Park before the Tahitians dumped them out of the competition with a 3-0 win in French Polynesia.
The navy blues win today sees them set a new record in the new competition format, albeit with the same goal difference as Waitakere United's win over Tefana last season, by virtue of goals scored.
Auckland City's win keeps them top of group B with three wins from three, their next match scheduled for Wednesday 17 April with AS Dragon at Trusts Stadium in Henderson.
In other group B action, Kiwi rivals Waitakere United notched 1 -0 win over AS Dragon of Tahiti in Papeete. Captain Jake Butler earned the win with a 43rd minute header.