Iran and South Korea have already secured the two automatic spots in Group A although third place, which offers a chance of qualifying via two playoffs, is still up for grabs between United Arab Emirates, Lebanon and Iraq.
It is in Group B however where things have really heated up, as a trio of traditional powerhouses vie for a top-two finish in hopes of booking their ticket to Qatar 2022 without any further fuss.
Here, we take a closer look at the three teams still in the running in Group B and assess their chances of direct qualification for the upcoming World Cup.
1st -- Saudi Arabia (19 points, goal difference of +5)
Games to come: China PR (March 24), Australia (March 29)
Saudi Arabia have arguably been the most impressive team in the third round of the Asian qualifiers and fittingly remain in pole position to secure automatic qualification.
Although initial expectations were that they would be Group B's third best team behind Japan and Australia, the Green Falcons would be undefeated in their first seven games -- racking up the 19 points that currently stand them in good stead.
Saudi Arabia's strength has come from their ability to share the workload through a well-rounded team effort, with no particular player a clear standout although they do have the talent capable of producing individual brilliance in the form of Salem Al-Dawsari, Salman Al-Faraj and Sami Al-Najei.
A 2-0 loss to Japan last time out has made things slightly trickier and Saudi Arabia do have to finish their campaign against Australia, although the situation remains straightforward enough.
A victory against an unimpressive China PR outfit on Thursday will guarantee the Green Falcons back-to-back appearances at the World Cup.
2nd -- Japan (18 points, goal difference of +6)
Games to come: Australia (March 24), Vietnam (March 29)
In direct contrast to Saudi Arabia's fortunes, Japan had to overcome a slow start to the third round of qualification after losing two of their opening three matches but look to be coming good at the right time.
Since losing to Saudi Arabia last October, the Samurai Blue have racked up five wins in a row and, while performances have remained unconvincing, the most important task remains qualifying for the World Cup for a 7th consecutive edition.
Japan coach Hajime Moriyasu does have some selection headaches ahead of their two upcoming ties with Europe-based stars like Takehiro Tomiyasu and Daizen Maeda, along with current leading scorer Yuya Osako, all absent.
Still, there remains sufficient quality at Moriyasu's disposal and -- as it the case with Saudi Arabia - the positive for the Japanese is their destiny remains in their own hands.
Should Japan beat Australia on Thursday, it would secure their progress but even a draw, which would maintain a three-point buffer between them and the Socceroos, should be sufficient given they finish off their campaign with game they are expected to win against bottom side Vietnam.
3rd -- Australia (15 points, goal difference of +9)
Games to come: Japan (March 24), Saudi Arabia (March 29)
Quite simply, Australia need something close to perfection if they are to secure an automatic berth at the World Cup given the luck of the fixture schedule has pitted them against both their main rivals in their final two matches.
After making a strong start to the campaign with three straight victories, the Socceroos have only managed one more victory in their past five outings and draws against China and Oman are now threatening to prove costly.
Their cause has been hampered by the absence of key men such as Tom Rogic, Harry Souttar and Aaron Mooy, and their need for more firepower up front has been illustrated with the introduction of Bruno Fornaroli -- the naturalised Uruguayan-born striker who is set to win his first senior international cap at the age of 34.
It is not beyond Australia's means to be able to pull off two results against Japan and Saudi Arabia and sneak into Group B's top two.
But just as they did for the 2018 edition of the World Cup, they might ultimately have to go through the playoffs to get to Qatar.