The full-back was withdrawn shortly before half-time of his country's friendly with New Zealand on Tuesday, and was visibly emotional during a presentation in his honour at the interval.
"I've received way more love and support than I deserve, and I am grateful for that," said Cha, who won 76 caps and featured at two World Cups.
"I might not have been a great player, but I always tried my best.
"My fans recognised that, and I am leaving international play a happy man."
South Korea won the game 1-0 thanks to Lee Jae-sung's late winner, after Son Heung-min had seen a first-half penalty saved by New Zealand debutant Stefan Marinovic.
"People might say we were lucky to score so late in the match," said victorious coach Uli Stielike.
"But given that we had the penalty in the first half and had two or three more great opportunities, I think we deserved to win tonight."
"We played against one of the top teams in Asia and we want to test ourselves against the best," added New Zealand coach Anthony Hudson.
"Overall, I thought the team was very competitive. I thought the players showed incredible spirit. I thought they tried from the start to finish to win the game."
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