Perfect conditions in Forsyth Barr Stadium defied external weather, and the game produced some classy football. Wellington generally looked impressive, and Southern mounted effective counterattacks, which might have nabbed a win.
This was never more so than when Jacob Schneider attacked up the right wing, and, despite Wellington looking to have boxed him in, the big German curved a dipping shot past Jacob Spoonley in goal, and after only two minutes, Southern United was 1-0 ahead.
Coach Luiz Uehara had demanded a strong start, and his players obliged in spades. But there was no relaxation for spectators as Wellington hit back almost immediately, when international Solomon Islander striker Henry Fa'arodo spun and laced in a fifth-minute athletic equaliser in United's crowded penalty area.
Wellington's pedigree showed as Colin Murphy masterminded elaborate passing moves from midfield and coach Matt Calcott's side switched play around, probing for openings, requiring United defenders to cover vast tracts of the pitch, and bravely launch some last-ditch tackles.
In contrast to Wellington's patient probing attacks, Southern showed incisive pace that had Regan Coldicott racing clear to ''score'', but he was denied by a linesman's flag.
Then Andrew Ridden broke through a tackle with the ball and accelerated clear from halfway. Spotting keeper Spoonley off his line, the big midfielder opted for a long range flighted shot - that took forever - but with spectators and Spoonley holding their breath, the ball flew narrowly over Wellington's crossbar.
Ajay Cunningham tested the Wellington defence with a similar flighted freekick that was headed clear, and centreback Joy pounded in a strong shot that was blocked.
Unfortunately, that was Joy's last involvement as he was hurt in a goalmouth melee, and limped off, to be replaced by Sam Mepham who went on to have an effective game.
Former Otago player Joel Stevens threatened with some pacey runs, Charlie Henry launched attacks across the field, and Jamie De Abreu, and Murphy prompted moves that threatened to unbalance the local defence.
In reply, Southern's Coldicott turned provider with an accurate cross that Cam Attwood headed high, and in a day for attacking defenders Cam Higgins also went close.
Keeper Batty made a fine double save from Stevens, but stood no chance as the former Green Island player drilled in a 60th-minute goal to give Wellington a 2-1 lead.
Heads slumped in dismay, but showing terrific spirit the team fought back within minutes and from a Ridden pass, Coldicott rode a fierce tackle, then used his pace to explode goalwards and slide the 63rd-minute equaliser past Spoonley.
Wellington then probably went on to play its most sustained attacking football against tired Southern legs, yet even under the cosh, coach Uehara's side continued to break out of defence and chase the win.
Coldicott again showed his pace and class to feed Southern's dynamic midfielder Morgan Day, who set up Henry Flood for a ripper of a shot that might have won the match, but instead only frightened a couple of passing seagulls.
A delighted Uehara contrasted with Wellington coach Calcott, who described his side's effort as ''laboured'' with too many missed opportunities.
The result moves United up level with WaiBOP on seven competition points, and looking forward to next week's match against the old enemy Canterbury in Christchurch on Sunday.
At Tahuna park, Southern United's Youth side beat Manawatu 2-1 in squally, wintry conditions, with a super opening goal by Lewis Jackson, and the second half winner - a penalty - slotted by James McGarry.
