The second-half stat that may concern Melbourne Victory

Melbourne Victory's concession of a late leveller during Saturday's enthralling derby cost them top spot on the Hyundai A-League ladder and highlighted a potentially worrying trend.

Dario Vidosic rose above a sea of bodies to nod in Scott Jamieson's cross in the 92nd minute and earn Melbourne City a valuable 1-1 draw at AAMI Park.

The underdogs had largely appeared directionless for the preceding 30 minutes, probing without potency in an attempt to respond to Ola Toivonen's opener.

REPORT: City deny Victory at the death in dramatic Melbourne Derby
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That sense of Victory comfort made the equaliser all the more surprising and gives Kevin Muscat a clear deficiency to address at the end of a six-match winning streak.

Vidosic's goal was, alarmingly, the fourth the Champions have conceded beyond the 90th minute in 2018 alone.

That's more than the three stoppage-time goals they gave up in the two previous years combined.

The late lapse denied them two points on this occasion and enabled Perth Glory to continue sitting atop the Hyundai A-League.

Tony Popovic's team would not be celebrating Christmas supremacy without the 93rd-minute winner Chris Ikonomidis scored in the 3-2 triumph over Victory back in October.

Muscat insisted in his post-match press conference that the Melbourne Derby didn't feel like a defeat, but encouraged his team to "take some learnings" from the setback.

The destination of the Premiers Plate could hinge on their success in heeding what is becoming a frequent lesson.