Angry fans called Wednesday for the resignation of coach Cho Kwang-Rae after South Korea suffered a stunning 1-2 defeat to underdogs Lebanon in the third round of regional World Cup qualification.
The official website of the Korea Football Association (KFA) was flooded with critical postings, with one suggesting a petition campaign to press the KFA to dismiss Cho.
Newspapers also lambasted South Korea for playing what Chosun Ilbo daily called a "game of sleepwalkers".
"Let's start a signature collection campaign to fire the coach," wrote one fan, Min Hong-Ki, on the KFA website.
"We have to get rid of him when we still have a chance. Otherwise, we won't be able to survive in the qualifying rounds," he said, noting Lebanon are ranked 115 places below South Korea.
"Do you still put trust in Cho who keeps saying the team has lost because it has no Park Ji-Sung and Lee Young-Pyo?" he said. South Korea's star striker Park and agile defender Lee have left the national team.
With the current team under Cho, South Korea are highly likely to miss the Brazil World Cup in 2014, Min said.
"Brother Kwang-Rae, I give you a red card. Get out!" another fan, Eo Jin-Kwon, wrote on the website.
A third fan, Maeng Young-Seok, said: "I am just lost for words. we have lost 2-1 to a team whom we had beaten 6-0. Aside from the result, the game was also bad. We had no goal in open play but only a penalty."
South Korea and Lebanon are now level on points at the top of Group B. Kuwait's 2-1 win over UAE on Tuesday kept alive the Kuwaitis' hopes of preventing one of the top two of progressing to the next stage of qualifying.