Two-time former champions Jeonbuk Hyundai Motors survived some anxious moments before beating Thailand's Chiangrai United 2-1 in their Asian Champions League Group H opener on Friday.

The South Korean giants, who won the title in 2006 and 2016, were 2-0 up with most of the second half remaining but were kept on edge by Chiangrai who put up a feisty display at the Milliy Stadium in Tashkent.

Lee Seung-gi put Jeonbuk ahead with a left-footed shot to the top right corner in the 36th minute as the eight times K League champions took a 1-0 cushion into the second half.

They doubled their advantage seven minutes after the restart after Chiangrai's Sanukarn Thinjom fouled Takahiro Kunimoto and Brazilian Gustavo converted from the spot.

Jeonbuk, however, found themselves under pressure as Chiangrai upped their game a notch with Phitiwat Sukjithammakul coming close with a shot from just outside the box in the 67th minute which sailed over the bar.

A minute later Ekanit Panya found the net for Chiangrai after a poor defensive clearance and with the Jeonbuk goalkeeper Lee Bum-young woefully out of position.

The Thais matched the Koreans in all departments of the game but despite their efforts were unable to create a clear chance at goal as Jeonbuk held on to grab three points.

Also in Group H, Gamba Osaka of Japan accounted for Singapore's Tampines Rovers 2-0 in Tashkent with goals in each half by their Brazilian forwards Patric and Leandro Pereira.

The Singaporeans, who were playing in the tournament for the first time in their history, fell behind to Patric's 26th minute goal but stayed in contention before Pereira's strike two minutes from time killed off their hopes.

Earlier in the day, Brazilian Mateus struck a second-half brace as Nagoya Grampus coasted to a fluent 3-0 victory over Pohang Steelers at the Rajamangala Stadium in Bangkok.

Nagoya had opened their campaign three days ago with a narrow 1-0 win over Malaysia's Johor Darul Ta'zim and the Japanese outfit's second straight victory on Friday took them to the top of group G.

The Pohang defence thwarted several chances in the first 30 minutes but their resistance began to wane as Nagoya continued to create chances.

The South Korean side finally succumbed to the pressure in the 34th minute when Manabu Saito teed up Yoichiro Kakitani to blast the ball past Pohang goalkeeper Kang Hyeon-Mu.

Pohang suffered a big blow in the 65th minute when they were reduced to 10 men after Shin Kwang-hoon handled the ball inside the box for his second yellow card, and Mateus made no mistake with the penalty.

Mateus, who had come in as a substitute 10 minutes earlier, added a second in the 82nd minute to seal the win.

Meanwhile Johor Darul Ta'zim edged Thailand's Ratchaburi 1-0 with Argentinian Leandro Velazquez finding the net in the 47th minute.

It was the first win for the Malaysians who now occupy second spot in Group G on a better goal difference with Pohang while Ratchaburi are fourth with two defeats from as many matches.