South Korea coach Dick Advocaat admitted his side lacked the quality to overcome Switzerland in their decisive 2-0 defeat in Hanover.
A Philippe Senderos header and Alex Frei's controversial late strike was enough to put the South Koreans out.
But Advocaat said: "We deserved more in the second half but we were just not good enough in the end.
"We knew beforehand that on set pieces they would be dangerous and they were, they controlled the first half."
The Dutchman also felt aggreived at referee Horacio Elizondo who ignored his assistant's offside flag, allowing Frei to net Switzerland's second.
The second goal was nonsense
South Korea's Lee Chun-soo
He added: "Most of the decisions didn't go our way and some were not to our liking."
Lee Chun-soo echoed his manager's comments.
He said: "The second goal was nonsense. We played so hard today but still have so much to learn."
Advocaat also revealed that his decision to employ an attacking formation may have cost his side dear.
He said: "We started with four strikers, and at the international level, that's quite dangerous. "That allowed them to play how they did and they kept attacking on counters."