Highlights -Argentina 4-1 South Korea
South Korea coach Huh Jung-Moo believed missed chances proved costly during his team's 4-1 loss to Argentina but was pleased with his players' spirit.
Gonzalo Higuain scored a hat-trick for Argentina in what was a comfortable win despite Lee Chung-Yong's goal making it 2-1 just before the break.
"We played well but there were some things we lacked and we missed opportunities," said Huh Jung-Moo.
"We fought well against a side who boast several star players."
South Korea's final match in Group B is against Nigeria on 22 June and their coach is confident they can reach the last 16.
"We have learned a lot from the game," added Huh Jung-Moo. "The result was unexpected but, regardless of the score, it's possible we can still make the last 16.
"Whether it's 4-1 or 3-1... (isn't) very meaningful. We marked [Lionel] Messi but didn't manage to get close enough to him.
"Our next match against Nigeria is now extremely important and it will decide whether or not we reach the Round of 16."
Argentina thoroughly deserved the victory, which was never in serious doubt from when Park Chu-Young directed the ball into his own net.
Diego Maradona's men doubled their lead when Messi and Maxi Rodriguez combined for Higuain to head home before Lee Chung-Yong halved the deficit by capitalising on a Martin Demichelis error with a superb finish beyond Sergio Romero.
Any Argentina nerves, however, were settled when Higuain tapped-in from close range and then he completed his hat-trick by heading home Sergio Aguero's cross.