Wellington's bid to secure a second consecutive finals berth may go down to the last day of the regular season after Sydney FC signed off at home with a comfortable 2-0 win at the SFS on Wednesday night.
The Phoenix could head into their final round clash with North Queensland on Sunday needing at least a point to fend off Newcastle for the last spot in the top six.
The Kiwis arrived for the Sky Blues' final home game with a patched-up side and it showed.
Their leaky defence rode its luck in the first half and had goalkeeper Danny Vukovic to thank for keeping things even at the break.
But a comical penalty that eventually found the back of the net on the third attempt via an own goal early in the second half, followed by a goal to replacement Brendan Gan sealed their fate.
Sydney midfielder Nicky Carle was awarded a penalty in the 54th minute after being brought down by James Muso, but hit his spot kick straight at the overworked Vukovic.
The ball came straight back to Carle who hit his second attempt straight back at Vukovic.
It rebounded off the keeper, ricocheting off Nick Ward's head and into the back of the net.
Carle quickly buried his face in his hands, as much out of embarrassment as disbelief.
Gan put the game out of Wellington's reach with an assured finish on 69 minutes after Shannon Cole shredded the defence before pulling his pass back into the box.
Sydney could have had the game in the bag before the half-time break if they'd buried two or three of the seven clear-cut opportunities presented them.
But they found Vukovic in irresistible form, albeit assisted by some far from clinical shooting in front of goal.
The game was only five minutes old when Sydney striker Bruno Cazarine beat the offside flag to go one-on-one with Vukovic, only to hit his attempt straight at the man he was trying to bypass.
Eleven minutes in strike partner Juho Makela carved out an opportunity for himself but couldn't get any power into his shot with only Vukovic standing in his way.
Three minutes later it was Carle's turn to go one-on-one with the keeper before directing his shot straight at the gloveman.
The chances kept coming.
Vukovic palmed away Hirofumi Moriyasu's effort on 22 minutes, made possible by a lovely Carle back heel.
Sydney skipper Terry McFlynn muffed his shot with Vukovic again there to pick up the dregs.
And just before half-time a goal-bound Cazarine volley brought out a brilliant one-handed save from the Phoenix custodian.
The penalty broke the deadlock and Gan completed the job but Sydney will feel they should have won more comfortably against a second-rate Wellington side.
Sydney FC 2 (Ward 54og, Gan 69)
Wellington 0