The seemingly unstoppable Green and Gold are back in the Middle East for a top-two showdown with the unbeaten Saudis in the port city of Jeddah on Friday morning (AEDT).
For the Green Falcons - in this the final phase of group qualification - Australia is their litmus test. How strong are the Saudis? We'll find out soon enough.
Thus far Saudi Arabia have taken all three points against Thailand and Iraq.
But the Caltex Socceroos are a different proposition and a real pointer to their qualification credentials under Dutch coach Bert van Marwijk.
And if those first two games are any gauge, the Saudis have seemingly perfected the art of scoring late with classy playmaker Nawaf Al Abed on target after the 80th minute against both Thailand (1-0) and Iraq (2-1, both from the spot).
Coincidentally, at club level the 26-year-old has also scored after just two seconds in what could be a world record
No doubt Al Abed is a danger. And that ACL final loss to Western Sydney Wanderers in Riyadh two years ago will still rankle with the Al-Hilal man.
That said, van Marwijk - who took his native Holland to the 2010 World Cup, losing to Spain 1-0 in the final – knows he’ll be pushed to the limit by the energy and relentless game plan of Ange Postecoglou’s men.
Australia will have an even fitter Tim Cahill to call on if need be and a month after bossing Iraq in Perth then UAE in Abu Dhabi, the unbeaten Aussies will be full of confidence that their game plan will produce joy in Jeddah.
It is the first of two huge games for both nations.
After Jeddah, Australia flies to Melbourne for a blockbuster date with Japan, while the Saudis host the UAE, both on October 11.
The Saudis were a powerhouse AFC nation in recent decades, winning the Asian Cup three times in the 80s and 90s and qualifying for World Cups from 1994 to 2006, including a fabulous World Cup USA, where they made the Round of 16.
But the landscape changed and the Saudis lost some of their lustre (though they are still ranked reasonably high, 52 in the world and fifth in Asia).
They will feel it’s their time to reassert their power in the region and winning this one will go a long way to supercharging their World Cup qualification hopes (though you feel a draw might be considered a good enough outcome).
Over recent times the Green Falcons looked to talisman and striker Yasser Al Qahtani (Wanderers fans may remember him from the ACL final against Al Hilal in 2014) to provide inspiration.
These days captain Osama Hawsawi is their defensive rock and Al Abed their key playmaker and danger. And a familiar face also returns – Nasser Al Shamrani. The controversial figure from the ACL final of 2014 may come off the bench late if the Saudis need a game changer.
Former Wanderers Matt Spiranovic and Tomi Juric will surely remember him.
This should be epic clash at the King Abdullah Sports City Stadium with the weather expected to be around 30 degrees for the 8.45pm kick off.
The only change to Australia’s squad at time of writing is the return of striker Apo Giannou, in for the injured Milos Degenek.