For the first time this season Sydney FC fans didn't wait for the final whistle before heading to the exit gates. A match that began with so much promise ended with the unfamiliar feeling - this season, at least - of defeat as the Sky Blues lost a match they had almost completely controlled.

Fatigued and frustrated after failing to turn on-field dominance into goals, Sydney succumbed to two late sucker punches from Nathan Burns, who did his best to stake his claim for a place in the 2015 Asian Cup squad. The Wellington Phoenix striker scored a superb solo effort before finishing with the composure that will make it difficult for Ange Postecoglou to justify an omission from his next Socceroos squad.

More immediately, it's clear that the January sales can't come soon enough for Sydney FC, who are now winless in four games and in danger of letting their stellar start to the season slip away.

Their superb play in the midfield was again at the forefront but, with a lack of pace and dynamic players to look for in the forward line, converting possession into chances remained a hope more than an ever-present threat.

"Look, it's a hiccup, definitely. I'm a fighter and I'll be working harder than ever and the boys have to work harder and they have to fight harder. If there's some that don't then they'll probably move on," Graham Arnold said.

Sydney's coach would have watched in envy as the pace of Phoenix's forward line tormented his side and a quick glance at his injury ward would have reminded him of why he couldn't reply similarly.

The flair and speed of Wellington's attackers should have broken the deadlock midway through the first half when Michael McGlinchey broke Sydney's offside trip with a neat back-heel that played Roy Krishna through on goal.

With Nathan Burns in tow, the Phoenix were odds-on to score before the linesman ruled the duo broke from the gates too soon, only for replays to suggest otherwise.

What the Phoenix offered in pace, Sydney did in class.

Through the composed midfield work of Terry Antonis and Dimitrijevic, they dictated the majority of possession. It took time and patience, but waves of possession eroded Wellington's defence.

The visitors' backline was caught napping by Bernie Ibini and Marc Janko who combined down the left to play the Sydney winger into the box.

Ibini cut back to find Shane Smeltz in front of goal who required just a simple finish to score against his former club. He did just that, but failed to account for the brilliance of Glen Moss who parried the ball into the path of Janko before producing another desperate attempt to turn the shot out to safety.

An uncharacteristic error by Milos Dimitrijevic allowed Burns to hone in on goal but even when he had sight of the target, he couldn't squeeze his shot through what little space Sydney's defenders gave him. Symbolic of the broader contest, but not a mistake Burns would make again. When Sydney didn't give him space, Burns created it.

The league's top goalscorer further staked his claim for selection for the Asian Cup squad at the expense of Pedj Bojic's pride.

Weaving easily past Sydney's right back before drifting away from Seb Ryall, he capped off a remarkable solo effort by slotting past Janjetovic at the near post to score his ninth of the season.

Burns sealed the result minutes later. AAP