An injury-time penalty rocked the AFC Champions League hopes of 10-man Guangzhou Evergrande on Wednesday as the favourites went down 2-1 to Seongnam FC in the last 16 first leg.

Fabio Cannavaro's 2013 winners recovered from going an early goal down and despite a red card to Li Xuepeng, the wealthy Chinese club looked set to escape with a 1-1 draw.

But there was late drama when Brazilian forward Ricardo Bueno took a tumble in the box and captain Kim Do-Heon held his nerve to bury his spot-kick in the 96th minute.

It sparked celebrations for Seongnam but they still have much work to do away next week, especially if Guangzhou welcome back injured Brazilian trio Elkeson, Alan and Rene Junior.

Seongnam went ahead through Jorginho on 23 minutes, but the Brazilian's effort was cancelled out just before half-time by Huang Bowen's stunning equaliser from 25 metres.

Guangzhou were reduced to 10 men in the 65th minute when Li caught Bueno in the chest with a high boot. And the Brazilian drew another pivotal foul when he won the penalty deep into stoppage time.

In Seoul, Takashi Usam's second-half brace gave Gamba Osaka a 3-1 away win over FC Seoul as the Japanese treble-winners took a giant stride towards the quarter-finals.

Seoul had not conceded in their previous six home games in the competition, but Gamba ended that defensive record with a superb counter-attacking display at Seoul World Cup Stadium.

The deadlock was broken in the 62nd minute when the ball was worked down the left flank to full-back Hiroki Fujiharu, whose cross was met by Usami with a firm volley that left goalkeeper Yoo Sang-Hoon helpless.

The visitors extended their lead 11 minutes later after more good work by Fujiharu, who sent a chip from the left byline to the far post where Koki Yonekura was on hand to slam the ball home.

Usami netted his second of the night with a superb individual effort with four minutes left, holding off two defenders before sending a low, left-footed shot past Yoo.

Yun Ju-Tae pulled a goal back for Seoul in stoppage time but the Korean side will need to score at least three goals next week in Japan to have any chance of progressing.