FC Seoul recovered from going a goal down and missing a penalty to beat Beijing Guoan 3-1 and reach the Asian Football Confederation Champions League quarterfinals in a dramatic last-16 match which saw three red cards on Tuesday.

The South Korean champions were stunned by an early strike by Frederic Kanoute, and then watched Serbian dangerman Dejan Damjanovic miss from the spot, before three goals in the final half-hour put them through to the last eight.

Ex-Premier League marksman Kanoute was the first to receive his marching orders, after a second yellow card for petulantly kicking away the ball, before Seoul's Adilson and Beijing defender Zhang Xinxin followed him down the tunnel.

The hectic second leg followed a tepid first installment of the round of 16 tie last week in the Chinese capital, and denied Beijing the first AFC Champions League quarterfinal in their history.

Seoul got off to a disastrous start when a defensive mix-up released Beijing's Kanoute in the box. The former West Ham, Spurs and Sevilla striker coolly finished to put the visitors 1-0 up after 8 minutes.

But Seoul nearly equalized when Colombian forward Mauricio Molina's bullet shot fired over, and Ha Dae-sung's flick header then drew a superb reaction save from Beijing goalie Yang Zhi.

After the break, Damjanovic and Molina both went close as Seoul pressed - and they got their break with a penalty on the hour mark, after the Colombian was brought down in the box by Beijing's Zhang.

Damjanovic's curling spot kick cannoned off the left post. But Seoul equalized just a minute later when Beijing keeper Yang fumbled a cross from Yun Il-lok into the path of Brazilian defender Adilson, who bundled it into an empty net.

Seoul needed two goals to win it, owing to Beijing's away goal, but they only had to wait 9 minutes for their second when Yun hammered home a loose ball in the box, after Beijing failed to clear a glancing header from Damjanovic.

And with 11 minutes remaining Seoul were given a helping hand by Kanoute, who earned his second yellow card and an early bath for shooting the ball into the net after the whistle had blown for offside.

Seoul also went down to 10 men when Adilson was sent off for an unusual challenge on Lang Zheng, in which he ended up with his legs wrapped around the Beijing defender.

But the hosts' numerical advantage was restored in the dying seconds when Zhang, who earlier gave away the penalty, compounded a dreadful night when he received a second yellow for impeding a Seoul player.

And with huge gaps appearing in Beijing's defense, and their goalkeeper caught out of position, midfielder Koh Myong-jin had time to steady himself and pick his spot for Seoul's third and final goal in the fourth minute of added time.

It's the third time that FC Seoul have been into the last eight of the AFC Champions League.