Ademola Lookman scored the only goal as Leicester beat Liverpool to leave the Reds six points off the top of the Premier League table.
Liverpool’s biggest chances came in the first half when Mohamed Salah had a 15th-minute penalty saved by Kasper Schmeichel and headed the rebound off the bar.
Sadio Mane then missed a couple of opportunities for Jurgen Klopp’s side before they were made to pay by the hosts in the 59th minute.
Former Everton forward Lookman, with only his fourth touch after coming on, took Kiernan Dewsbury-Hall’s pass in his stride, beat Joel Matip and rifled a shot past Alisson – Leicester’s only shot on target.
Leicester, missing several first-team players, hung on despite relentless late Liverpool pressure – just six days after blowing a 3-1 lead to lose on penalties against the same opposition in the Carabao Cup quarter-finals.
With only their second defeat of the season, Liverpool are now six points behind leaders Manchester City, while Leicester – who have won just two games out of seven – move up to ninth.
Klopp later said: “Maybe if I watch the game back, I’ll see that we were just unlucky. I’m not sure that’ll be my analysis. I didn’t like our performance, to be honest. We played a very strange game. We had chances – they had one shot on goal and that’s fine.
“The reason for the defeat is clear. They had to play two days ago, they had to fight through this really intense period and they did it really well. If we had played like we’re able to play, I think we’d have still been the winner. But we didn’t do enough to beat Leicester so they deserved to win.
“There were too many performances below normal level. My job is to figure these kind of things out before the game. Who is in shape and all these kind of things.
“So often these boys gave me the opportunity to say ‘wow, what a game!’ – tonight it’s ‘wow!’ but in completely the other way. It didn’t look good. It didn’t look like us, and that’s obviously the one thing we have to think about and change immediately.”