Having seen all their three representatives progress into last year’s quarter-finals, Saudi Arabia once again emerged the most successful country in this year's AFC Champions League with Al Ahli and Al Shabab securing their places in the last eight.

In the far east, China PR, Korea Republic and Japan each boast a side in the next phase with Guangzhou Evergrande, FC Seoul and Kashiwa Reysol all advancing. Buriram United, meanwhile, continued their amazing run by eliminating Bunyodkor with a goalless draw, while Esteghlal and Lekhwiya sealed progression despite their respective draws at home.

The match
FC Seoul 3-1 Beijing Guoan
FC Seoul came from a goal down to see off Beijing Guoan 3-1 at home to seal progression on the back of their goalless first-leg draw. Having stormed into the last eight in all their three past Asian appearances, the K League champions made it to the quarter-finals for a fourth time with a sterling comeback.

Four goals, three red cards and a missed spot-kick were the numbers which suggested how fiercely the game was contested. The Chinese visitors got off to a good start, when Frederic Kanoute capitalised on a defensive error to open the scoring early on. FC Seoul laid siege to the Beijing goal for the remainder of the opening half, but the rivals defended gallantly to keep their slight lead intact.

The hosts came out firing on all cylinders after the restart, with the equaliser coming on the stroke of the hour mark. Dejan Damjanovic may have seen his penalty denied by the woodwork, but Yun Illok set Adilson up to pull the hosts level a minute later. The provider then turned scorer on 70 minutes to put his side ahead, before Koh Myongjin struck in stoppage time to complete the home side's comeback victory.

The surprise
Bunyodkor 0-0 Buriram United
Despite entering the game in Tashkent on the back of a 2-1 home win, few gave Buriram a realistic chance of sealing an aggregate triumph over two-time semi-finalists Bunyodkor. The hosts, after all, have reached the knockout stage on six consecutive occasions, while the visitors were only the first Thailand club to progress beyond the group phase in a decade.

With a 1-0 win enough to see them through, Mirdjalal Kasimov's hosts pressed forward from the outset. Scott Cooper's visitors, though, demonstrated resolve and reduced their rivals to few chances. Bunyodkor attacked relentlessly, with Oleksandr Pyshu seeing a second-half effort disallowed for offside. But Buriram's back-line proved solid, with the Thais bravely holding on to seal an unlikely place in the next round.

The other attractions
Despite being held to a 1-1 opening-leg draw at El Jaish, last year’s runners-up Al Ahli progressed with a 2-0 home win. Bruno Cesar and Mustafa Al Bassas each struck in the opening half as the hosts prevailed to progress at the debutants' expense.

Al Shabab, meanwhile, showed visiting Al Gharafa no mercy by firing home three unanswered goals to advance 5-1 on aggregate. Argentinian forward Sebastian Tagliabue was on target in each half to give the hosts a 2-0 lead, before Mohannad Abu Radeah completed the rout with a stoppage-time strike.

With compatriots Al Ahli and Al Shabab cruising, Al Hilal could manage no better than a 2-2 draw at Lekhwiya which ensured the Qataris qualified. Entering the return trailing by a first-leg 1-0 deficit, the visitors' woes were compounded with the home side two goals up on 52 minutes. Salman Al Faraj and Mohammed Al Shalhoub struck late to provide Al Hilal with a lifeline, but the decisive match winning-goal never came and Lekhwiya became the sole Qatari representatives in the next round.

In what proved to be a lacklustre return match, neither Esteghlal nor Al Shabab Al Arabi found the back of the net. Despite the draw, the Iranian hosts clinched their first quarter-final spot in the Champions League courtesy of their 4-2 opening victory.

There was little surprise in east Asia, with both Guangzhou Evergrande and Kashiwa Reysol continuing their smooth run. In the process, the former crushed Central Coast Mariners 3-0 at home with tournament top-scorer Muriqui scoring one and earning a spot-kick. The latter, for their part, prevailed 3-2 at home to inflict a fourth straight defeat over the 2006 winners in two years.

The player
21-year-old midfielder Yun Illok proved the liveliest of FC Seoul’s players setting up one and scoring another as the capital club swept past Beijing.

The stat
- FC Seoul have so far eked out four wins in each of their home matches, while Bunyodkor have been held to draws in their four home outings

What they said
"It is a shame that we could not win the game. We had our chances to win but Buriram played well defensively. We missed many chances and we are the only ones to blame for the result," Bunyodkor coach Mirdjalal Kasimov

Round of 16 second leg results
21 & 22 May
Al Shabab 3-0 Al Gharafa
Al Ahli 2-0 El Jaish
Lekhwiya 2-2 Al Hilal
Esteghlal 0-0 Al Shabab Al Arabi
FC Seoul 3-1 Beijing Guoan
Bunyodkor 0-0 Buriram United
Guangzhou Evergrande 3-0 Central Coast Mariners
Kashiwa Reysol 3-2 Jeonbuk Motors