The Sky Blues of Sydney came up just short in controversial circumstances when they lost their first match of the season to local rivals Western Sydney on the same night and they will head south well aware that Melbourne City are one of the few teams they have yet to beat in this most scintillating of Sydney seasons.

In the FFA Cup final last November, City got the better of Graham Arnold's men thanks to a first-half Tim Cahill goal, while in the first A-League meeting between the two clubs, in December, it was only a late penalty that allowed Sydney to secure a point after Fernando Brandan's spectacular long shot had given the visitors the lead.

City have taken a while to adjust under new coach Michael Valkanis, who succeeded John van 't Schip in late December, and this will be the first time he pits his wits against Arnold on the sideline.

Valkanis has tried to make City more defensively accountable, but it was their goalscoring that caught the eye on Saturday when they crushed Wellington, rarely an easy proposition in New Zealand, 5-1.

The win lifts them to outright third on the A-League table, a long way behind Sydney and Melbourne Victory, but more to the point it will be a huge confidence booster at a critical time of the season.

The team had won only twice under new coach Valkanis and both those victories (over Central Coast and Western Sydney) had come when their opponents were reduced to 10 men.

But the 2-2 draw with Brisbane last week, when a collection of fringe players and youngsters promoted from the youth team came back from a 0-2 half-time deficit to grab a share of the spoils, was more important than the scoreline or the point it produced.

The performance and the lift to the spirits it gave everyone around the club proved to the first team regulars – seven of whom were suspended for that game – that there was genuine competition for places in the starting line-up and that the club possessed the depth to mount a challenge in the last third of the season when injuries, tiredness and red and yellow cards begin to take a bigger toll.

Valkanis made some changes to the starting 11 that travelled across the Tasman, but he retained several players who often find themselves on the bench – including midfielders Nick Fitzgerald and Anthony Caceres – in the starting line-up.

And his selection proved spot on, despite the fact that Cahill was left on the bench alongside Argentinian playmaker Nicolas Colazo, both only entering the fray late in the game, although the latter managed to weigh in with City's final goal.

"We had to win. We knew what our goal is and where we want to be at the end of the year," Valkanis said afterwards.

"We were well organised [because] in the first 10 minutes we weathered the storm and they had a couple of good opportunities.

"I can honestly say that our luck has changed a bit. After that opening when they put us under pressure I think we started to control the game with and without the ball.

"We created some very good chances so it was pleasing to score goals because this team can score and in the past five or six games, the team has created that much that we haven't been able to show for that.

"In this game I thought, with probably less opportunities than we've had in the past, we were clinical and could have had some more goals."

While catching Sydney – who, despite Saturday night's loss are still 17 points to the good – is only a remote mathematical possibility, Valkanis hasn't give up hope of putting more pressure on Victory in the final two months of the campaign.

"We feel that it's coming together at the right stage of the season," he said.