Big-spending Chinese champions Guangzhou made their intentions clear in Group H, hammering last season's beaten finalists.

Jeonbuk, who started the K-League season with a 3-2 win over Seongnam on Saturday, were always chasing the game, after Cleo and big-money signing Dario Conca put the Chinese side 2-0 up at the break.

Conca set up Brazilian striker Cleo for the third on 69 minutes, before Jeonbuk pulled one back through substitute Jeong Seong-Hoon.

However, Lee Jang-Soo's Guangzhou added further goals from Conca and 2011 Chinese Super League MVP Muriqui to complete a big win.

In the other Group H encounter, Thai Premier League champions Buriram United opened their maiden Champions League campaign with a surprise 3-2 win over J.League champions Kashiwa Reysol.

Goals from Jirawat Makarom and Uzbek midfielder Asqar Jadigerov had Buriram 2-0 up after 39 minutes, before Reysol hit back after the break.

Ricardo Lobo set up both goals, with Junya Tanaka pulling one back on 55 minutes and impressive full-back Hiroki Sakai levelling the encounter soon after.

But Buriram were not to be denied, as Ghanaian Frank Acheampong set up Makarom for a 78th-minute winner.

In Group G, J.League runners-up Nagoya Grampus and Korean FA Cup winners Seongnam battled out a thrilling 2-2 draw.

Josh Kennedy's penalty and a Mu Kanazaki goal had put Nagoya ahead after Heverton's opener, but the Brazilian netted a stoppage-time equaliser.

A-League leaders Central Coast Mariners played out a drab 0-0 draw at Tianjin Teda.

In Group A, United Arab Emirates champions Al-Jazira staged a comeback to record a 4-2 win over AFC Cup winners Nasaf Qarshi.

Trailing 2-0 after 12 minutes in Uzbekistan, Al-Jazira took all three points thanks to goals from Juma Abdullah, Abdullah Mousa, Bare and Ricardo Oliveira.

Elsewhere, Bruno Correa's 84th-minue winner saw Iran's Sepahan to a 1-0 win over Al-Nasr, while Nam Tae-Hee's goal helped Qatari outfit Lekhwiya to a 1-0 victory at home to Al-Ahli in Group C.

In Group D, Al-Shabab and Al-Gharafa, from the UAE and Qatar respectively, played out a 0-0 draw.

The other match in Group D also ended all square, as Al Hilal of Saudi Arabia came from behind to draw 1-1 at home to Iranian club Persepolis.