The anticipated wake for sacked title-winning boss Claudio Ranieri took on an unexpectedly celebratory air at the King Power Stadium, as Jamie Vardy netted his first top-flight goals since December 10 either side of Danny Drinkwater's spectacular long-range strike.
Philippe Coutinho pulled a goal back for the visitors but Leicester were able to move out of the relegation zone, while Klopp's men are fifth having played a game more than Manchester City and Arsenal immediately above them as well as sixth-placed Manchester United.
"If we make our best game and play really good and we lose I have to accept it, that's football," Klopp told Sky Sports, before criticising his players for leaving their preparation after a 16-day break from competitive action on the training field.
"We did not do enough. It looked like we'd never spoken about the strength of Leicester. That's the real problem.
"I spoke in the dressing room about it. That's not enough, for sure. That's not even close to being enough.
"We have to work, obviously and try with everything we have to do better next time. It is really hard to see what we would usually be able to do in this performance.
"Not good in offence, not good in defence - that's how you lose football games.
"There is no reason at this moment for this. You can always find excuses but I am not ready to look for an excuse."
Next up for Liverpool is a pivotal showdown with Arsenal at Anfield.
Facing top-four rivals has not been the main problem for Klopp's men this term - four of their five Premier League defeats this season have now come against sides who started the match in the relegation zone - but he suggested there will be a lengthy inquest into their woes against Leicester.
"We have a week to prepare and we have to show a reaction. That's what we have to do," he added.
"We have to perform differently to what we did. We can be much better, we have shown it already. Not doing it feels really disappointing.
"Thank God we don't have to play again tomorrow. After you win and you lose you have to analyse, show the boys and react on it again."