Off contract at the end of this current campaign, Italiano used his post-match press conference to announce his decision to quit the 'Nix after three seasons with the A-League Men club.
Italiano's exit came after a derby thrashing in which Wellington were way off the pace, headlined by a comical own goal from Josh Oluwayemi that led to the goalkeeper being substiuted at halftime.
Oluwayemi's 24th-minute howler looks destined to be a permanent feature on goalkeeper gaffe compilations after the Phoenix No.1 completely misjudged a Jake Girdwood-Reich clearance at Sky Stadium in Wellington on Saturday.
Approximately 75 metres out from Wellington's goal, Girdwood-Reich cleared a ball downfield and caught Oluwayemi out of his box.
Whether the wind played a part or not, the No.1 misjudged the flight of the ball and was forced to backpedal before heading it into his own net.
Oluwayemi's blunder was the catalyst for a first-half implosion and the goalkeeper was so out of sorts he was subbed off at halftime by Italiano and replaced by Alby Kelly-Heald.
Auckland only had three shots on target in the first half but led 4-0 at halftime.
Guillermo May found the back of the net with a well-taken finish in the 41st minute.
Jesse Randall grabbed a double, his second ending Oluwayemi's afternoon when he chipped the goalkeeper, who was stranded in no-man's land.
Kelly-Heald was brought on at the break that appeared to bring a level of calmness to proceedings until Lachlan Brook struck his eighth goal of the season in the 74th minute.
Auckland have won all six of their derby meetings to date.
Corica's side remain second with their sizeable victory, cutting the lead held by first-placed Newcastle, who host Macarthur on Sunday, to just one point.
Wellington, meanwhile, dropped to 10th and are now on the hunt for a new coach.
