Squandered chances started to mount up - new signing Jason Walker headed over the bar from point blank and at final count, Livesey and Doney blew a hat-trick of chances each - but Culpepper had the final say when, picked out from 30m by Irvine, he skirted past defender Hone Fowler, with his low drive evading the despairing dive of Sergio Bustos and ricocheting in off the post.
Josh Nelson earned a booking and Culpepper was also shown yellow for retaliating after being hacked down inside the penalty area by Kwesi Dadzie, with the referee also ignoring a big handball from defender Billy McClure.
North Shore United won yesterday's only other game in division two, 3-0 over Warkworth.
In Saturday's league action, league leaders Hibiscus Coast showed their first sign of wobbles with a 4-3 loss to Waiuku, although it hardly dented their march towards the club's first-ever silverware and they're still only a win away from gaining promotion.
Mangere United eased past relegation-bound Papakura City 2-0, Matamata and Western Springs were deadlocked 1-1 and Fencibles United downed Onehunga Mangere 2-1.