Istiklol threw the group wide open after beating 2019 champions Al Hilal SFC 4-1 on Matchday Four, with the Tajik club taking top spot from the Saudi Pro League champions on goal difference with both teams on seven points.

Shabab Al Ahli are also still in the running after playing their best football of their 2021 campaign to beat AGMK FC 3-1 on Matchday Four, placing them third in the standings on four points.

Quarter-finalists last year, Pakhtakor are yet to get their first win of the 2021 campaign, collecting three points from their first four games. Yet another setback will consign the Uzbek champions to group stage elimination.

Tractor are in a slightly better position, sitting second on six points - two behind UAE's Sharjah - but will also need a win to keep their hopes of clinching the sole automatic ticket to the Round of 16.

Victory against Air Force Club will go a long way in taking Sharjah closer to the Round of 16, as it would move them to 11 points. In fact, should Islamic Republic of Iran's Tractor FC fail to beat Pakhtakor of Uzbekistan in the group's earlier tie on Monday, a Sharjah win over Air Force Club will book them their last 16 ticket with a match to spare.

Back-to-back wins for Al Sadd against Jordan's Al Wehdat saw the Qataris jump up to second place in Group D with seven points, one adrift of leaders Al Nassr of Saudi Arabia.

Islamic Republic of Iran's Foolad are third on five points and need to win their final two matches to stand a chance of advancing.

Al Nassr lead the group with eight points, one ahead of Qatar's Al Sadd while Al Wehdat are at the bottom of the standings with a solitary point and out of the running for the Round of 16. Foolad Khouzestan FC, meanwhile, are third on five points and still in the running to advance.

It has been yet another difficult campaign for Al Rayyan, with the Qatar club failing to advance to the Round of 16 at the 10th time of trying. Fc Goa, meanwhile, have relished taking on some of Asia's biggest teams in their debut campaign despite it having been a steep learning curve.

Islamic Republic of Iran's Persepolis - with 12 points in the bag - have all but qualified for the Round of 16 while victory for Al Wahda will keep them within sight of going through.