Melbourne City coach Patrick Kisnorbo has labelled his players "naive" for coughing up a pair of late goals in a 2-2 draw with Adelaide United.

City appeared destined for a second consecutive win to open their A-League Men's title defence after marksmen Jamie Maclaren and Andrew Nabbout scored.

But Adelaide captain Stefan Mauk and winger Ben Halloran converted in the final 15 minutes of a Saturday night thriller at Coopers Stadium.

Mauk followed in a Kusini Yengi shot which hit the near post in the 78th minute before Halloran, in the 90th minute, pounced on a City blunder.

Halloran floated a 20-metre shot from an acute angle after intercepting City 'keeper Thomas Glover's pass to a flat-footed teammate.

"It's a learning curve for us," Kisnorbo said.

"The first goal (conceded), a deflection off the post.

"And the second one, we were a bit naive, especially in the last couple of minutes.

"So we learnt a lesson."

City largely outplayed Adelaide until the Reds' unheralded revival, with vaunted attacking trio Nabbout, Maclaren and Mathew Leckie terrorising their hosts.

Star striker Maclaren was gifted silver service from Nabbout for the easiest of tap-ins in the 28th minute.

Nabbout capitalised on a shrewd lobbed through-ball from Connor Metcalfe, tearing into space and - as Reds 'keeper James Delianov advanced - delivered a pinpoint pass to Maclaren one metre from goal.

And in the 61st minute, Nabbout found time and space along the right flank before cutting inside Josh Cavallo and scoring with an audacious 16-metre curling shot with the outside of his right boot.

Nabbout almost scored again 10 minutes later with a low shot that drifted just wide of the far post, before Mauk's opportunistic goal sparked Adelaide.

"It was hard to take, to be 2-0 down," Adelaide coach Carl Veart said.

"I thought we played some good stuff ... but they're a good side, they punish you and don't need many opportunities.

"But the boys responded well, that spirit, and to comeback the way they did was fantastic.

"If we went another four or five minutes, I reckon we would have got a winner."