Williams, a half-time substitute in the clash at Oldham's SportsDirect.com Park, gave Melbourne City FC the lead with virtually his first contribution, slotting home a low left-footed shot in the 48th minute afer a neat passing move.

But Oldham, which created a number of clear-cut chances in both halves, equalised late in the match through a looping effort from Spanish substitute Miguel Llera.

In the second pre-season hit-out of Melbourne City FC's UK camp, John van't Schip sent out an experimental squad in the first half, with 2013-2014 National Youth League players Ross Archibald and Paulo Retre - alongside traillists George Evans and James Poole - included in the starting XI.

Aaron Mooy and Massimo Murdocca were situated in the midfield and the pair were at the heart of some promising passages of play, with pleasing contributions from Iain Ramsay and James Brown.

It was Brown who had the first real chance of the match when he found space inside a crowded Oldham penalty area, but perhaps was startled by the room afforded and sliced his effort wide of the target.

Melbourne City played the ball around nicely in the opening exchanges, but was nearly punished by the home side in the 21st minute as Jonson Clark-Harris swiped at a shot from just 10 yards out, but failed to connect with any purpose and the chance slid wide.

Brown then had another opportunity seven minutes later, which came after blocked efforts from Retre and Evans, but his shot lacked power and Paul Rachubka saved easily in the Oldham goal.

Clark-Harris threatened again a minute later, but wasted another opportunity when he should have made goalkeeper Tando Velaphi work.

Arguably Clark-Harris would have finished Oldham's next opportunity had James Dayton squared to him unmarked, but a superb and timely interception from Archibald halted that particular attack.

Van't Schip's side applied pressure of its own shortly afterwards and Archibald almost showed his worth at the other end of the pitch, but headed a corner from Mooy just over the bar.

Back-to-back chances to Oldham's Mike Jones saw the first-half close out in a stalemate, with Melbourne City enjoying the better periods of possession, but with Oldham having created the better chances.

With the break came five changes with Robbie Wieleart, Jason Hoffman, Ramsay, Mooy and Brown withdrawn, while trialist Chris Chantler, Patrick Kisnorbo, Nick Kalmar, Mate Dugandzic and David Williams entered the fray.

Just three minutes after the restart, the latter pair combined clinically for the opener with Dugandzic threading a clever through ball as Williams beat the offside trap and finished well with a low strike past Rachubka.

The goal came after a neat passing move but soon after there was a flurry of substitutions from the home side which disrupted play slightly and Oldham started to tighten and threatened Melbourne City on numerous occasions.

However, despite the continued pressure from the Latics, Melbourne City's defence, led by Kisnorbo, held strong and repelled the home side, which looked to finish strongly.

It was only late in the match that Oldham looked as though it would pinch an equaliser with Jones having an effort blocked in the 82nd minute, before Velaphi saved from his follow-up.

But Oldham did grab an equaliser on 85 minutes in unusual fashion as Spanish substitute Llera looped an unorthodox effort over Velaphi's head and into the net, with both sides sharing the spoils in an entertaining hit-out.