Asia's elite face little margin for error

National derbies take centre stage in this week's AFC Champions League Round of 16, with two-time winners Al Ittihad taking on Al Hilal in an all-Saudi affair, while city rivals Gamba and Cerezo do battle in Osaka in what promises to be an epic contest.

In the west, the Iranian duo of Sepahan and Zob Ahan entertain Bunyodkor and Al Nassr respectively, while in the Far East, K-League champions FC Seoul and Suwon Bluewings will have home advantage as they seek to overcome Japan’s Kashima Antlers and Nagoya Grampus respectively.

Tianjin Teda travel to K-League leaders Jeonbuk Motors, facing an uphill battle to maintain Chinese interest. The same can be said of Al Sadd, who visit hosts Al Shabab seeking to keep Qatar’s only hopes alive. previews what shapes as an intriguing round - the only one-off knockout stage prior to the final - where the margin for error for all 16 teams will be slim.

The match
Al Ittihad-Al Hilal
By any standards this match-up can be considered a classic of Asian football. On the home front, these arch-rivals are two of the perennial title-contenders, while at continental level both are among Asia's most accomplished teams. Al Ittihad may boast a better Asian record, being the only side to have lifted the trophy on more than one occasion. However, Al Hilal can take heart from their superior record in domestic competition, with their recent title-defense marking their thirteenth Saudi championship success, five more than Ittihad.

A 2-1 home win over Najran saw Hilal finish the season unbeaten and despite drawing against Ittihad in both legs, the Riyadh giants enter the re-match with a clear historical edge, having won four more games than their rivals in their past 26 meetings. Hilal's hopes rely on their on-song marksman Yasser Al Qahtani, while spearheading Ittihad's line-up is the talismanic Mohammed Noor.

Managing Hilal is none other than Gabriel Calderon, the man responsible for taking Ittihad to their eighth Saudi title two years ago. With Hilal fans will hope the Argentine's knowledge will be a trump card, Ittihad can rely on the experience of the newly returned Dimitri Davidovic, who has guided the Jeddah giants to three national championships.

The other attractions
With one spot in the last eight already sealed for Saudi Arabia, Al Shabab and Al Nasr will be hoping to make it a treble with victories at Al Sadd and Zob Ahan respectively. The former enter the game against the Qatari hosts with a solitary-goal win over Al Faysali on Friday in the season's concluding match, but the latter must put their 5-2 defeat at Al Ittihad behind them when facing formidable Iranians Zob Ahan.

Having recently retained the league title, Sepahan can turn their full focus to the Asian front and a meeting with Bunyodkor. Despite losing the league's closing game 2-1 at Saipa, the 2007 runners-up will be clear favourites on home soil, provided they can reproduce the form that has seen them win the group campaign ahead of Al Hilal. The Uzbek visitors, for their part, have recently clawed themselves back into winning form, particularly on the evidence of their recent 4-1 demolition of Olmaliq.

Gamba are the overwhelming favourites against city rivals Cerezo, having won six and drawn three of their nine previous meetings. The 2008 Asian champions boast arguably the J.League’s most creative midfield, crowned by the silky skills of Yasuhito Endo. Meanwhile, their attack is spearheaded by Adriano, with the Brazilian twice on target in Sunday's 2-1 defeat of Albirex Niigata to move top of the league’s goalscoring list.

Revenge will be on Kashima's mind when they cross swords with Korea Republic champions FC Seoul. Having bowed out at the same stage in the previous edition with a 1-0 loss against Pohang Steelers, the Japanese heavyweights will be keen to atone this time around. In another Japan-Korea Republic encounter, Nagoya Grampus will look to put a stuttering opening to their title-defense behind them, however Suwon will draw inspiration from their resounding 3-0 drubbing of Gamba last year.

Although ace-striker Lee Dong-Gook is nursing an injury picked up against Pohang a week ago, Jeonbuk proved they are not lacking in attacking options, with another in-form striker Kruno Lovrek hitting the winner against Gangwon FC on the weekend to move top of the K-League standings. However, the ambitious Tianjin come into the match on the back of a 2-1 home victory over Jiangsu Sainty.

The player
Chen Tao has been instrumental in Tianjin's qualification for the second round, with his goals and assists undoing the likes of Gamba and Jeju United to date. The midfielder's attacking flair will be key if the Chinese are to overcome Jeonbuk.

What they said
"Cerezo are the one team we really, absolutely, do not want to lose to, especially at home in Asian competition. In a sense it does feel a bit of a waste that we have to play a Japanese team so early on though. I would have liked to have played them in the latter stages instead," Gamba Osaka defender Satoshi Yamaguchi.

2011 AFC Champions League Round of 16 fixtures:
Tuesday 24 & Wednesday 25 May
Jeonbuk Motors-Tianjin Teda
Gamba Osaka-Cerezo Osaka
Al Ittihad-Al Hilal
Al Sadd-Al Shabab
Zob Ahan-Al Nassr
Suwon Bluewings-Nagoya Grampus
FC Seoul-Kashima Antlers