Gamba Osaka got off to a confident start in defense of their title with a 3-0 win over China's Shandong Luneng FC on Tuesday, while Nagoya Grampus staged a second-half comeback to beat South Korea's Ulsan Hyundai 3-1, as the group stages of the 2009 Asian Football Confederation Champions League got under way.

Brazilian striker Montera Leandro put the reigning Asian club champion ahead in the 20th minute, and a second-half penalty from Yasuhito Endo extended their lead, before substitute Hayato Sasaki's 79th-minute effort wrapped up a comfortable three points for Gamba in their Group F game at Expo '70 Stadium.

In Ulsan, Grampus fell behind on a first-half goal by Jin Soo Cho in their Group E opener but turned the tables on their hosts with two second-half headers from defender Maya Yoshida and Brazilian forward Davi, while the latter's midfield compatriot Rafael Magnum made the game safe with Nagoya's third three minutes from time.

Japan's two other participants in this year competition, Kashima Antlers and Kawasaki Frontale, take on South Korea's Suwon Samsung Bluewings and China's Tianjin Teda, respectively, in Groups G and H on Wednesday.

Under the competition's revamped format, 32 teams from a broadly defined Asian region spanning the Middle East to Australia are divided into eight groups of four, with the top two from each group going through to the knockout rounds.