LIVERPOOL — Second-string Liverpool were thumped 3-0 by Crystal Palace as Ismaila Sarr struck twice for the visitors in the League Cup yesterday, booking the London side’s spot in the quarter-finals and piling more misery on Arne Slot’s struggling side.

Holders Newcastle United dispatched Tottenham Hotspur 2-0, Arsenal beat Brighton & Hove Albion 2-0, Manchester City came back to down second-tier Swansea City 3-1 and Chelsea edged past Wolverhampton Wanderers 4-3 in other fourth-round ties.

Slot rested most of his regular starters — as did the other major Premier League clubs — leaving Liverpool to suffer their sixth loss in seven games across all competitions.

The match at Anfield was fairly even before Sarr scored in the 41st minute when Liverpool defender Joe Gomez attempted to clear the ball but teed it up instead for the Senegalese player, who unleashed a blistering shot past keeper Freddie Woodman.

In a torrential downpour that matched the Reds fans’ mood, Sarr doubled Palace’s lead seconds before the break when he latched onto a lovely reverse pass from Yeremy Pino.

Liverpool were reduced to 10 men when Amara Nallo was sent off in the 79th minute for taking down Justin Devenny, his second red card in two senior appearances.

Pino added to Liverpool’s misery with the visitors’ third goal in the 88th minute.

“It’s not of Liverpool standards to lose six out of seven,” Slot told Sky Sports.

Asked if Saturday’s Premier League game at home to Aston Villa was a must-win, Slot said: “Every Liverpool game is a must-win.”

The night marked the first time Liverpool had lost a domestic cup match at Anfield by three goals without scoring since February 1934 in a 3-0 defeat by Bolton in the FA Cup.

It was also the league champions’ third loss to Palace this season.

“I don’t know how often this happens when you play the champions three times within three months, and you win three times. So credit to the players,” said Palace boss Oliver Glasner.