Beijing Guoan were held to a 0-0 draw at Workers' Stadium Tuesday night in the first leg of the AFC Champions League last 16 clash despite playing out the final 30 minutes against ten-men FC Seoul.

Choi Hyo-jin picked up two bookings in the first 15 minutes of the second half from referee Andre El Haddad to leave Choi Yong-soo's side shorthanded for the final half an hour.

But the K-League champions weathered the storm and will go into the second leg in Seoul next Tuesday knowing a win on home soil will see them advance to the quarter-finals for the second time in three seasons.

"It was a tough game like expected," said Choi. "Beijing were very aggressive in the first half but, fortunately, we were not bad in the first 45 minutes either.

"Luckily we didn't concede any goals. It was a shame that it was only a draw but in the next round we hope to have a better result with better preparation.

"We were not here for just one point. We were prepared for a win and to score more goals. Due to the unexpected injury in the first half (to Sergio Escudero), we failed to reach our goal."

Choi's team shaded the first half with Sergio Escudero firing off an effort that went just over the bar with only 10 minutes on the clock while Dejan Damjanovic went closer still, charging through the Beijing defence before firing off a shot that was marginally off target.

Beijing, aiming to qualify for the quarterfinals of the competition for the first time, had their chances too, with Zhang Xizhe brilliantly controlling a long ball into the Seoul penalty area before curling his attempt at goal just wide of the target.

Choi was forced into a change in the dying minutes of the half as Escudero pulled up with a hamstring injury that saw him replaced by Yun Il-lok. That enforced alteration to the FC Seoul line-up, however, was minor compared to the upheaval that would come in the second half.

Choi Hyo-jin picked up his first booking in the 52nd minute when he brought down Freddy Kanoute on the edge of the penalty area while, just eight minutes later, a foul on Zhang Xizhe saw Haddad brandish a second yellow card for the full back.

Beijing attempted to make the most of the man advantage, with Darko Matic taking aim from the edge of the area only to miss the target with his side-footed attempt while Kanoute's attempt from similar range was just wide.

Try as they might, though, Beijing were unable to find a way past the FC Seoul defence, leaving the tie finely poised going into next week's second leg.

"I am quite satisfied with the 0-0 result," said Beijing coach Aleksandar Stanojevic. "But I'm a bit unhappy about the fact that we didn't take anything frm having home advantage. But this is the AFC Champions League and none of the opponents are easy.

"Today we were doing well in the game and I was expecting goals, that's why I didn't feel any early need to make changes in the game. It was a difficult game, we created our chances. I have no reasons to blame any of my players. We hadn't thought about having one more player on pitch at all. That player deserved the sent-off.

"Korean teams are generally good in Asia, but we still have our chance and that is why we have to prepare with 100% effort for the next game."