Nine places in the knockout stage are still up for grab as the 2012 AFC Champions League group campaign goes down to the wire on Tuesday and Wednesday. In the continent's west, Saudi giants Al Hilal are hoping to join compatriots Al Ittihad and Al Ahli in the Round of 16, while Iranian duo Persepolis and Esteghlal are also strongly favoured to qualify from their respective sections.

In the east, all four Korea Republic representatives are hopeful of advancing and, while 2008 winners Gamba Osaka have been eliminated, Japan’s Nagoya Grampus are on the verge of progression. Meanwhile, J.League champions Kashiwa Reysol need to defeat in-form Jeonbuk Motors and hope other results go their way. Elsewhere, Guangzhou Evergrande are the only Chinese side still in contention, while Bunyodkor face a must-win at home against Pohang Steelers. Join as we preview in detail the showdowns across Asia.

The match
Buriram United-Guangzhou Evergrande
When Group H bottom side Buriram United line up with second-placed Guangzhou Evergrande on Tuesday both sides know that they are on the threshold of history. The Thai hosts can seal their first-ever place in the Round of 16 if they win and Kashiwa Reysol drop points against leaders Jeonbuk Motors. The visitors, for their part, can secure qualification with a victory, while a point may be enough to take the Chinese debutants through as long as Jeonbuk avoid defeat against Kashiwa.

Added to the home support, Buriram coach Attaphol Puspakom's side can take heart from their early form which saw them stun Kashiwa and Guangzhou, although they must make do without suspended Cameroonian defender Yves Hermann Ekwala. In order to rest his key players, Guangzhou coach Lee Jang-Soo fielded a second-string line-up in Friday's 3-1 defeat by Dalian Shide. However, there are still concerns for the Korean coach with first-choice goalkeeper Yan Jun serving a suspension and striking-ace Muriqui nursing a hamstring strain. Meanwhile, top-scorer Dario Conca is likely to miss the showdown as a result of internal disciplinary action. In the sections other match, Jeonbuk need just a point at home to make it through to the knockout stage for a third consecutive time.

The other attractions
Group A's Esteghlal finished third in the Iranian league on Friday, narrowly behind runners-up Teraktor Sazi on goal difference and just a point adrift of champions Sepahan. However, they have plenty of reason for optimism with a draw at the already-eliminated Nasaf enough to seal second spot behind Al Jazira, who face a determined Al Rayyan. Iranian hopes lie on the shoulders of top-striker Arash Borhani, who netted a brace in their 3-0 defeat of Al Rayyan in the previous round, before again being twice on target as they fired three unanswered goals past Naft Tehran.

Similarly, Group B's Bani Yas need just a home draw against Pakhtakor to secure the runners-up place behind group winners Al Ittihad. However, the United Arab Emirates heavyweights must remain wary of their opponents’ recent form, having thrashed Mashal Mubarek on Thursday to move third in the domestic league standings.

Leading second-placed Persepolis by a point courtesy of their previous 1-0 win in Tehran, Group D front-runners Al Hilal know a draw against third-placed Al Gharafa at home is enough to take them through. The Saudi giants can even make it through with a defeat should Persepolis fail to win at the eliminated Al Shabab. Despite finishing a humble 12th place in the Iranian league, Persepolis' chances in the continental competition look bright as a triumph over the bottom side can seal passage regardless of the other result.

Group E's Bunyodkor face a straightforward scenario with nothing less than three points at home against Pohang Steelers enough to salvage their hopes. Boasting a 2-0 away win in the previous meeting, the Uzbek enter the re-match boosted by their recent 2-0 defeat of Olmaliq which saw them return to the summit of the local standings. Pohang, meanwhile, travel to Tashkent hoping to push aside some recent lacklustre form. The other game of the pool pits the qualified Adelaide United against the already-out Gamba Osaka, with the former seeking to win the group with an away victory.

Sharing Group G's top place level on seven points, Seongnam and Nagoya can both progress with a point each against Tianjin Teda and Central Coast Mariners respectively. Should both lose, Seongnam can advance alongside Central Coast on goal difference at the expanse of the Japanese.

Player to watch
Buriram's Cameroonian striker Franck Ohandza completed a brace despite losing to Jeonbuk 3-2 on matchday 4. The 20-year-old's goalscoring form could be the key as the Thai champions aim to become the first side from their country to reach the knockout stage since 2003.

The stat
4 - Having dominated the group campaign in the past two editions, K-League sides are likely to see their four representatives through to the knockout stage for a second time.

What they said
"For me, this game is as big as a grand final and to get into the second round of the Asian Champions League would be a fantastic achievement. The players know how big this game is so we'll be ready," Central Coast coach Graham Arnold

AFC Champions League Matchday 6 fixtures
15-16 May
Group A: Nasaf-Esteghlal, Al Rayyan-Al Jazira
Group B: Bani Yas-Pakhtakor, Al Ittihad-Al Arabi
Group C: Lekhwiya-Al Nasr, Sepahan-Al Ahli
Group D: Al Hilal-Al Gharafa, Al Shabab-Persepolis
Group E: Bunyodkor-Pohang Steelers, Gamba Osaka-Adelaide United
Group F: Brisbane Roar-Beijing Guoan, Ulsan Hyundai-FC Tokyo
Group G: Nagoya Grampus-Central Coast Mariners, Tianjin Teda-Seongnam Ilhwa
Group H: Jeonbuk Motors-Kashiwa Reysol, Buriram United-Guangzhou Evergrande