Socceroos veteran Mark Bresciano has warned his side to expect the unexpected when Australia take on Iraq on Tuesday in Sydney.
Defeating Iraq in their final AFC qualifier will mean the Socceroos will qualify for their third-straight World Cup.
If the Socceroos fail to win the match, their fate will depend on the result of Oman's trip to Jordan.
Australia's qualifying campaign had appeared in trouble before an impressive draw with Japan on June 4 and last Tuesday's win over Jordan.
Iraq's last hopes of reaching the World Cup were snuffed out by their defeat to Japan last Tuesday and have their internal problems, but Bresciano has acknowledged the threat the Lions of Mesopotamia still pose.
"Football is changing, because, a lot of countries where years ago you probably think it's a walk in the park but it's not like that anymore," Bresciano, 33, told Football Federation Australia's website.
"They've showed that anyone can beat anyone these days, it all comes down to your performance on the day and how focused you are on the day."
"... Like we've all said, it's not done yet because we've still got Tuesday and we're the only ones that have got something to lose, so that's when it's going to be very difficult for us and we have to be in the right mindset to get this win on Tuesday."
With a place in the World Cup perhaps just 90 minutes away, all the tickets for Tuesday's match at the 88,000-capacity Stadium Australia have been snapped up.