Australia lost ground in Group B of AFC World Cup qualifying, held to a 1-1 draw by Iraq.

This was a fourth consecutive qualifying stalemate for Ange Postecoglou's side, which had won its opening two group games against Iraq and United Arab Emirates.

Despite defeat in the reverse fixture, Iraq was the better side this time around and was unfortunate to fall behind to a Mathew Leckie header after 39 minutes.

It looked as though the Socceroos would see out the second half and claim a crucial win, but substitute Ahmed Yasin deservedly levelled for the host 14 minutes from the end to earn a share of the spoils.

Victory against UAE back in Sydney on Tuesday will now be crucial if the Socceroos are to secure a top-two spot and qualify automatically for the finals in Russia.

Iraq made the brighter start, with Ali Adnan cutting in from the left to fire over and Mohannad Abdul Raheem then forcing a smart stop from Mitchell Langerak.

Amjed Kalaf then lifted a finish over the crossbar and their profligacy proved costly as Australia took the lead through Leckie - after Jackson Irvine and Aaron Mooy had fired warning shots.

With six minutes of the half to play Leckie met Mooy's corner superbly and powered his head inside the left-hand post.

Iraq was grateful to Mohammed Hamed as he denied Robbie Kruse, Tomi Juric and Mooy either side of the break, while Langerak was alert to parry Ahmed Ibrahim's effort.

As the game wore on Iraq found another gear and secured a point after 76 minutes as Ahmed Yasin slid in to convert Ali Adnan's low cross from the left, Langerak having been unable to claim.

The host team needed a peace of expert defending in stoppage time, though, as the Socceroos almost stole victory in the closing moments - Tim Cahill's header needing to be cleared off the line from Mooy's corner.