|Disappointing start for the defending champions Pohang [GALLO/GETTY]
South Korea's Pohang Steelers lost their first game as Asian Champions League defending champions when they were beaten 1-0 at Australia's Adelaide United.
Breaking from the halfway line following a Pohang corner, Adelaide teenage striker Matthew Leckie pressured Park Hee-chul to stab the ball past the latter's goalkeeper in first-half stoppage time.
Leckie was credited with the goal by match officials, as the ball possibly deflected off him last.
Adelaide defeated Pohang twice in the group stage two years ago, going on to make the 2008 final, and maintained a perfect record against the South Korean club.
The champions from two years ago, Gamba Osaka packed the midfield to stifle hosts Suwon Bluewings in a goalless draw.
Suwon were happy for the point with little form behind them as the South Korean league had yet to start.
The other Group G match was also a 0-0 draw, as Henan Construction of China dominated Singapore Armed Forces without any luck. Amado Diallo, Zheng Lu and Xiao Zhi all hit the posts in a squandered opportunity for three points.
Beside Adelaide in Group H, China's Shandong Luneng also emerged winners from a valuable 1-0 win at Japan's Sanfrecce Hiroshima.
Shandong Luneng's winner came via a header in the 76th minute from China international striker Han Peng.
Pakhtakor, the only club to qualify for every Asian Champions League since the new format in 2003, started Group C with a 1-0 win over Emirates host Al-Ain. Pakhtakor took advantage of their few chances to score during a counterattack capped by Artur Gevorkyan in the 59th.
Iran's Sepahan and Saudi Arabia's Al Shabab renewed acquaintance two years after two showdowns won by Sepahan. This time Al Shabab salvaged a 1-1 draw with a second-half goal by Faisal Al Sultan.
There were plenty of goals in Group D, in which Iran's Mes Kerman came back to defeat Emirates visitor Al Ahli 4-2, and Saudi's Al Hilal downed Qatari host Al-Sadd 3-0.
Iran international Mehrzad Madanchi looked like spoiling Mes' day with a 2-1 goal for Al Ahli just before the hour mark, but Mes rallied when Mahdi Rajabzadeh equalised in the 75th, and Mehrdi Rajab Zadeh hit the winner 10 minutes later.
Ali Samareh added a last-minute score to help boost spirits at the struggling Iran Pro League club.
Al Hilal were on the board after only nine minutes thanks to the first of a pair by Yasser Al Qahtani.
He headed in a cross from Thiago Neves, and volleyed in the clincher in the 66th. Neves' last-minute goal made sure the trip home to Saudi Arabia was much more comfortable.