Alfie Mawson's first-half winner produced one of the shock results of the season as the Premier League's bottom club downed opponents previously unbeaten in 18 games.
Liverpool's below-par performance was all the more unfathomable as it came after they had ended the unbeaten record of leaders Manchester City, and Klopp's miserable night took a turn for the worse when he was involved in a spat with a Swansea supporter.
"He was shouting at me all the time and I reacted once," Klopp said of the second-half incident.
"I must remind myself I'm a human being and not just a professional manager who takes that all the time. They can say whatever they want, at one point I turned to him and said, 'Please!' It was only one moment when I had enough, it wasn't to do with the fact we were 1-0 down.
"I'm sure I am not the first manager who has had a problem with him there, he must be a season ticket holder. It was my fault as well. I should not react, but I didn't say anything bad. I just showed I wasn't happy about what he was saying."
Roberto Firmino almost rescued a point for Liverpool in stoppage time when his header came back off a post.
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But Klopp was left bemoaning a result which leaves Liverpool six points adrift of second-placed Manchester United and three behind Chelsea in third.
"I'm more frustrated with the performance than the result and I'm angry because it was not a good game," Klopp said.
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