Missing regulars Colm Kenny and Jordan Culpepper, coach Duncan Lowry brought in Van Ewert and Dean Styles as cover.
The league's top scorer Jerahl Hughes was the first to trouble either goalkeeper, forcing Joshua Fsadni off his line to block the shot after a break down the right.
Five minutes later, Hughes was in the action down the right again, whipping in a dangerous-looking cross that evaded everyone. It was to be a pattern of play repeated several times.
While Metro had looked comfortable on the ball, they hadn't created a clear-cut chance until Craig Squires rose above the City defence to meet a corner and put the ball beyond keeper Tom Pamment after 20 minutes.
They went close to doubling their lead a few minutes later when Rafi Mohammadi was given space and time to create room for a shot that whistled past the top of the upright.
Hughes switched over to the left and City launched several promising attacks down that wing, with the Metro defence at times looking vulnerable. But the closest City came to equalising in the first half was from a corner, with the ball stopped on the line bringing an appeal for hand ball that was dismissed.
City showed glimpses of the type of play that could see them unlock the defence, but rarely found a quality finish.
As the second half progressed, Metro protected their lead through smart defensive work to catch the attackers offside and by sheer weight of numbers.
Chances fell to Hughes, Simon Millet, Andrew Cooper and Fawwa Ali, the best when Hughes and Cooper were through on goal, only for Fsadni to beat them both to the ball.
With the top two meeting next weekend, the game in hand, and the fact that City have yet to visit North Shore, Lowry will know that all is not completely lost, and will be looking for a much more commanding performance when his side visit Manurewa next weekend.