They were made to pay, falling behind on the 15-minute mark. Waisake Sabatu was caught in possession, Suburbs swept upfield and the move ended with a simple tap-in to give the visitors a deserved 1-0 lead.
It was only after they'd fallen behind that United realised they had a game on their hands. They responded by becoming more assertive and committed in midfield, with Miroslav Tvaroh leading the recovery with his trademark tackling and raking cross field passes in an attempt to outflank the Suburbs' defence.
United went on to dominate the rest of the half and were rewarded when Suburbs keeper Mitchell Stuart-Hill was pressured into palming the ball into his own net from a corner to take the sides in 1-1 at the break.
The home side continued to press after the break and deservedly took a 2-1 lead when the Suburbs keeper again fumbled under pressure from Seule Soromon, the ball was squared to the recalled Jorge De La Torre who stroked home from the edge of the box. The lead was short-lived. Missed tackles resulted in a Suburbs equaliser and this was compounded when non-existent marking allowed the visitors a free header at close range to give them a 3-2 lead.
This advantage was quickly nullified when Jonatan Almendra crashed the ball home into the top corner of the net with a superb strike from a free kick awarded on the edge of the box which gave the Suburbs keeper no chance - 3-3 and all to play for.
Both teams sought the winner and the game became very open, with opportunities created and missed at both ends, Suburbs in particular missing an open goal from long range when United keeper Matt Borren fluffed a clearance.
United may feel this was a game where they were their own worst enemy. Having worked their way into the game, creating scoring opportunities and scoring two good goals, they conceded the advantage through a series of errors - being caught in possession, missing tackles and failing to mark up and challenge when defending their own goal.
Cooksley had a strong game for United once he had moved to the back four, marshalling the home defence. Tvaroh worked tirelessly in midfield before being substituted midway through the second period. Soromon posed a constant threat up front.
Meanwhile, in Capital 2 Douglas Villa continued their winning ways by travelling over the hill and defeating Lower Hutt 3-0.
This makes it four wins out of five for Villa and sees them strengthen their grip on second place. Leading 1-0 at the break courtesy of a well worked team goal finished off by Tim Woodcock, Villa continued to apply the pressure after the break and were rewarded with two goals against an opposition down to 10 men after a red-card tackle. Ben Logan added Villa's second goal and Woodcock slotted the third.
"We played well right from the start. We knew we had to and the boys came up with the goods. They played out of their skins," Villa coach Troy Burling said.
"The whole defence deserves a mention, they played as a unit and kept another clean sheet."
In Capital 3, Wairarapa United seconds remain at the top of the table after their 6-2 thumping of Inglorious White Socks in Wellington, with Thomas Hemi chipping in with five of the goals.
White Swan Greytown and Gardner Electrical Masterton fought out a 1-1 draw.