Guangzhou R&F made an ideal debut in the Asian Champions League with a 2-0 win over 2008 champion Gamba Osaka.
Striker Abderrazzaq Hamedallah scored in the 10th minute and Wang Song deflected in a free kick 10 minutes from time to hand the Chinese Super League club a notable win.
Guangzhou R&F manager Cosmin Contra was impressed with the defensive cohesion of his team, which earned a spot in the tournament through qualifying.
"We prepared well for this game and had a little bit of an advantage. They are in the pre-season and we had played two official qualifiers," Contra said. "We scored on the first occasion we had and this changed the game. After that, we knew our defense is very good, and we made a very good defensive game, even if our attack was not as inspirational.
"Maybe this can look like a surprise because we won over the champions of Japan. It is true we are the first Chinese team to beat Osaka here in Japan. They are a very, very good team and I think they are a favorite in the group."
Coach Kenta Hasegawa said his J-League champions would "get woken by this."
"It was very disappointing to lose the game at home," he said. "Since we still have five more games to play in the group, we'll improve the quality of our game and collect points in order to get through."
Thai Premier League champion Buriram United beat Seongnam 2-1 in the other Group F match, with Prakit Deeprom and Gilberto Macena's goals giving them a 2-0 lead by the 20th minute -- Narubadin Weerawatnodom's own goal gave the South Korean club a late consolation.
In Group E, 2006 winner Jeonbuk Motors drew 0-0 with Kashiwa Reysol, while China's Shandong Luneng won a five-goal thriller in Vietnam against Binh Duong.
Substitute Yang Xu scored his second goal nine minutes from fulltime for the 3-2 win, as all the goals came in the second half.
Shandong Luneng's Wang Yongpo opened the scoring two minutes into the second half, only to see striker Ganiyu Oseni equalizing for the home team within a minute.
Wang Qiang's own goal four minutes before the hour mark earned Binh Duong the lead, but after Yang hit back five minutes later for Shandong, the halftime substitute headed home to cap a slick move from the visitors, and claim all three points.
In the western zone, 2014 semifinalist Al Ain had to share the points with Saudi Arabia's Al Shabab after a 0-0 draw.
Al Ain's Ghana striker Asamoah Gyan, the leading scorer in last season's ACL, had the better of the chances but couldn't find a way past Al Shabab keeper Waleed Abdullah.
Uzbekistan champion Pakhtakor opened with a 2-1 win over Naft Tehran to lead the group.
Iranian club Persepolis leads Group A after its 3-0 win over Qatar's Lekhwiya. Al-Nassr of Saudi Arabia and Uzbek giant Bunyodkor shared the spoils in a 1-1 draw.
Defending champion Western Sydney Wanderers open their campaign with a tough away opener in Group H against Kashima Antlers in Japan on Wednesday night, while 2013 champion Guangzhou Evergrande hosts 2014 semifinalist FC Seoul.