Sydney controlled almost the entire encounter, starting the stronger side, creating an abundance of opportunities and finally finding the lead through marquee man Filip Holosko six minutes from time.
That goal, which saw Holosko cut in from the right and curl a delightful strike around a stubborn Moss, appeared to end a prolonged period of frustration for the visitors. With the Phoenix unable to create much in attack, turning over the ball too often and lacking their usual fluency, Sydney were somehow unable to take advantage.
Denied by the goalkeeper, the referee and the width of the Westpac Stadium crossbar, Sydney were providing plenty of evidence for why they are the least prolific team in the league, with only 11 goals from 11 games.
They also boast the best defence and, with such a scarcity of goals, it was no surprise when the first half finished level, especially since all 11 of Sydney's fixtures this season have done just that. But that streak could have easily been snapped in a first half that featured plenty of goalmouth action, with Moss twice preventing his opponents and referee Peter Green twice waving away penalty appeals.
The reprieves appeared to shock the Phoenix to life and, after a discouraging opening quarter, they began to pose some tests of their own. Jeffrey Sarpong enjoyed the home side's best chance of the half as the Phoenix threatened down the left flank, though that same sideline was continuing to prove problematic at the other end.
Tom Doyle had been recalled to replace Matt Ridenton at left back but Wellington's issues continued as several of Sydney's best opportunities originated in that area. But the closest Sydney came to opening their account came from 30 yards out, when Brandon O'Neill's brilliant free kick cannoned off the crossbar with Moss well beaten.
Sydney's mood would have further soured after the break when, after blatant simulation from Hoole conned Green into awarding a penalty, Moss turned away the same man's spot kick with a rock-solid right hand.
That feat did little to inspire the Phoenix, however, with Sydney allowed plenty of possession to manufacture more chances. Wellington's best source of hope seemed to be on the break, with Krishna turned around the post from one raid, but it was a set piece that eventually saw Doyle bundled over and allowed the Fijian to play hero.
Wellington Phoenix 1 (Krishna 90)
Sydney FC 1 (Holosko 84)
HT: 0-0