Ismaila Sarr struck twice in the first half and Yeremy Pino grabbed the third to condemn Arne Slot’s side to a sixth defeat in their last seven games in all competitions.

Slot fielded a weakened team as he prioritised Liverpool’s crucial games against Aston Villa, Real Madrid and Manchester City over the next two weeks.

But it was still another embarrassing result for Liverpool, coming hot on the heels of a 3-2 loss at Brentford on Saturday that further dented their spluttering Premier League title defence.

The Reds have lost their last four league matches and trail leaders Arsenal by seven points.

“It’s not Liverpool standards to lose six out of seven,” Slot said. “But it’s only two days to rest, play the next one, then only two days’ rest, play Real Madrid and then a few days more for Man City.

“Everyone can have his opinion about it, but with the squad we are having maybe 15, 16 first team players available, this is the choice I’ve made.

“The pressure was already very high for the upcoming week where we again have to face three very difficult teams.”

Assailed by criticism of their defensive failings and the poor form of blockbuster summer signings Alexander Isak and Florian Wirtz, Liverpool’s fall from grace has been stunning.

Isak, Wirtz, Mohamed Salah and Virgil van Dijk were all absent as Slot made 10 changes and fielded teenagers Kieran Morrison, Rio Ngumoha and Trey Nyoni.

It was a gamble that never looked like working and FA Cup holders Palace have now defeated Liverpool three times in the space of just 80 days.

They beat the Reds on penalties in the Community Shield and 2-1 in the Premier League.

Slot switched to a back three in a bid to revitalise Liverpool, but the move backfired when Joe Gomez’s mistake allowed Sarr to rifle home from 12 yards in the 41st minute.

Senegal winger Sarr increased Palace’s lead on the stroke of half-time, netting from Pino’s pass in front of the shell-shocked Kop.

Liverpool substitute Amara Nallo was sent off in the 79th minute for a professional foul on Justin Devenny.

Pino slotted in Palace’s third in the 88th minute to book a last eight trip to Arsenal.

Man City survive scare

Holders Newcastle beat Tottenham 2-0 at St James’ Park to set up a quarter-final visit from Fulham.

Fabian Schar headed Newcastle’s opener from Sandro Tonali’s 24th-minute corner and Nick Woltemade nodded in the second goal from Jacob Ramsey’s cross on 50 minutes.

Manchester City came from behind to win 3-1 at second-tier Swansea, securing a quarter-final at home to Brentford.

City, featuring 10 changes from the 1-0 defeat at Aston Villa last week, trailed to Goncalo Franco’s 12th-minute goal.

But Jeremy Doku’s deflected strike dragged City level in the 39th minute and Omar Marmoush scored in the 77th before Rayan Cherki’s stoppage-time effort completed the comeback.

Arsenal, who haven’t won the League Cup since 1993, beat Brighton 2-0 at the Emirates Stadium to make it eight successive wins in all competitions.

Ethan Nwaneri lashed into the bottom corner in the 57th minute and Bukayo Saka struck from close range with 14 minutes remaining.

Aged just 15 years and 302 days, Max Dowman became Arsenal’s youngest ever starter and boss Mikel Arteta said: “It’s definitely something special.

“He has shown incredible skill to run past players at that level aged 15.”

Chelsea will visit third-tier Cardiff in the last eight after the Blues’ understudies won 4-3 at struggling Wolves.

Andrey Santos, Tyrique George, Estevao Willian and Jamie Gittens scored for Chelsea, with Toluwalase Arokodare and David Wolfe, who struck twice, replying for Wolves.

Chelsea striker Liam Delap was dismissed in the 86th minute for two bookings, prompting boss Enzo Maresca to label him “stupid” and “embarrassing”.