31/08/2017 9:22 PM AEST | Updated 31/08/2017 11:00 PM AEST

Socceroos Lose 2-0 To Japan In Crucial FIFA World Cup Qualifier

But Australia's hopes for Russia 2018 aren't over just yet.

Masashi Hara via Getty Images
It's all uphill from here.

That's definitely not the result Australia needed.

The Socceroos have been dealt a knock against Japan in Saitama on Thursday night, after losing 2-0 in a crucial FIFA World Cup Qualifying match that could decide whether Australia heads to Russia in 2018.

Beating Japan on any occasion, let alone on its home turf, is no easy feat -- the last time Australia beat Japan in any fixture was in a 2009 World Cup qualifier at the MCG and haven't been victorious against them, while away from home, since 1969.

And while both teams had early opportunities in front of goal on Thursday, it was Australia that started hard and fast on the pitch, finding its feet quickly and dominating much of the possession with ease throughout the first half.

This match was always going to be an important one -- the equation was simple: An Australian win means qualification to the 2018 Russia World Cup.

With captain Mile Jedinak and Aussie Premier League midfielder Aaron Mooy both ruled out for the game, the Socceroos' hopes for the World Cup fell to the likes of Australia's young talent in Massimo Luongo, Tom Rogic, Matthew Leckie and Robbie Kruse.

And to their credit, they looked pretty good for the opening 40 minutes. But from there it was all Japan.

One striking opportunity by Leckie on the edge of Japan's goal-box, somehow skimmed between what looked like every defender Japan had on the field, to roll past goalkeeper Eiji Kawashima and bounce off the goalpost. Cue the nail-biting.

Japan also had some notable players missing however, after Shinji Kagawa, Keisuke Honda and Shinji Okazaki -- who are three of the country's best players -- were all named to start on the bench for the game.

But it wasn't long before Japan took the chances also given to them. On the back of a well-picked cross from the sideline, striker Takuma Asano slotted an easy goal past Australian keeper Mat Ryan to leave the match at 1-0 just before the half-time break.

From there, Australia started the second half pretty sluggish while Japan ramped up the attack on Ryan's goalmouth. If it wasn't from some game-saving defending from Trent Sainsbury, it looked like the Socceroos were on a path to falling even further behind.

As time ticked down, on came the Socceroos' firepower -- forward Tomi Juric and veteran star Tim Cahill were substituted into the match. Each passing moment in front of Japan's goalmouth then became a little stronger, a little more tense, but no equalising goal came.

The Japanese attack didn't let up. There are reasons why they currently sit at the top of Australia's World Cup qualifying group, and boy did they show them to the Socceroos -- at times, making them look downright average.

And that's when Yosuke Ideguchi smacked an absolute screamer of a goal past Ryan in the 82nd minute and it was effectively game over for Australia. 2-0.

The win for Japan means they're straight through to the World Cup, but the loss for Australia means it's all uphill from here for the Socceroos.

So, what now?

Australia continues to sit third in its World Cup qualifying group, equal on competition points with second-place Saudi Arabia. That means all eyes are now on the Socceroos' next match against last-place Thailand in Melbourne on Tuesday.

That match is a definite must-win if there's any chance of Australia qualifying for Russia 2018, but also relies on Japan beating Saudi Arabia in Jeddah, leaving second place free for the Socceroos to take.

While the equation just got a little more difficult for Australia, it's still a pretty simple one: A win against Thailand leaves us in with a chance. Anything else and we can pretty much kiss Russia goodbye.

What Happens If We Finish Third?

This isn't good. Nobody wants this.

First, we'd have to play a team like Uzbekistan, who currently sit third in the other Asian qualifying group, both home and away.

If we win, we'd then take on the fourth-placed CONCACAF (North and Central America group) side.

Right now, Panama is in a close battle with the United States for fourth spot in the CONCACAF standings. Beating either of them would be tough. The group also contains Costa Rica, who humbled Uruguay, Italy and England at the 2014 World Cup.

And so the bottom line is -- it all comes down to beating Thailand on Tuesday. Australia's hopes of a fourth consecutive World Cup berth depend on it.