J.League side Kashiwa - Champions League semi-finalists in 2013 - hammered Vietnamese opponents Binh Duong 5-1, with Japan international Masato Kudo twice on target.
It took the hosts 43 minutes to break the deadlock at the Kashiwa Hitachi Stadium, but Kudo's opener was quickly followed by David Vrankovic's own goal.
Kim Chang-soo, Kudo and Hidekazu Otani took the game beyond the visitors before Ganiyu Oseni netted a consolation goal for the visitors.
Yang Xu was the hero and villain for Shandong Luneng in their 4-1 defeat to Jeonbuk Motors as he cancelled out Edu's opener before being sent off late on.
Following Yang's equaliser, Han Gyo-won, Lee Jae-sung and Leonardo sealed the points for Jeonbuk, with Yang then shown a second yellow for attempting to score a goal with his hand 11 minutes from time.
Korean FA Cup winners Seongnam are up and running in the competition as Ricardo Bueno's penalty and a second-half Hwang Ui-jo strike sealed a 2-0 win over Japanese champions Gamba Osaka.
Gilberto Macena starred for Buriram United in their Group F victory over Guangzhou R and F after Ko Seul-ki cancelled out Lu Lin's opener.
The Brazilian forward struck late on to ensure a 2-1 win that moves Alexandre Gama's men top of the pool.
