Johor Darul Ta'zim (JDT) were left to rue a host of missed chances as the reigning Super League champions fell to a 2-0 defeat to Pohang Steelers in Thursday's Asian Champions League (ACL) Group G match in Bangkok.
The defeat was JDT's third in four group games in the ACL.
Following the defeat, JDT now stand almost no chance of advancing to the last-16 of the tournament.
The South Korean side scored through midfielder Lee Seung Mo (33rd minute) and defender Kang Sang Woo (37th) for a well-deserved win at the Rajamangala Stadium.
Pohang are now second in the group with nine points, below leaders Nagoya Grampus of Japan, who defeated bottom side Ratchaburi of Thailand 3-0 at the same venue, on 12.
JDT had several scoring opportunities, with Safawi Rasid having the best chance in the game when his free-kick rattled the Pohang post in the 16th minute.
Coach Benjamin Mora said: "We had the shots, free kicks, everything, but we didn't score.
"We also made mistakes during the game. In the ACL, if you make one mistake, you will concede a goal.
"I think we did well in the opening 30 minutes. We were composed and even hit the post with Safawi's free-kick," said Mora.
"We had opportunities to move forward, but we could not take the advantage."
JDT will play Nagoya tomorrow, followed by their final group game against Ratchaburi on Wednesday.