Cerezo boss disappointed despite Champions League win
"It was our first international tournament and I am happy with this win," Cerezo's Brazilian coach Levir Culpi told reporters. "This win has a significant meaning as this is now in our club history.
"But I am not satisfied with the scoreline, we should have scored more. To get through the group stage, we may come up with a situation that involves goal difference."
Jeonbuk Motors joined Cerezo at the top of Group G after the 2006 winners beat Chinese champions Shandong Luneng 1-0 at Jeonju World Cup Stadium.
Elsewhere, last year's runners-up Zob Ahan rebounded from a poor start to kick-off their Group D campaign with a 2-1 home win over Emirates.
Nabil Daoudi put the United Arab Emirates side in front after just six minutes but Seyed Mohammad Hosseini and Igor Castro replied for the Iranians.
"I confess that we didn't play well enough in the opening half, although we created some chances," Zob coach Mansour Ebrahimzadeh said.
"Emirates gradually tired in the second-half and we took advantage of their lack of strength. We got better after the break and we can get better game by game."
Twice champions Al Ittihad of Saudi Arabia also recorded an opening victory when two goals from Abdelmalek Ziaya helped them to a 3-1 win over Piroozi of Iran.
However, South Koreans Suwon Bluewings had to settle for a point from their Group H clash with Sydney FC, playing out a 0-0 draw despite the Australians being reduced to 10-men after just 33 minutes.