The Belgian centre back had disastrous seven-minute spell before halftime as he first ignored a shout from his goalkeeper Danny Ward to leave a low cross from Alexander-Arnold and lunged in to make an attempted clearance, only to mishit the ball so it looped over Ward and in at the far post.
Darwin Nunez was then played through on goal by Alex Oxlade-Chamberlain and dinked a shot over Ward that bounced back off the far post.
The back-tracking Faes tried to clear the ball but only succeeded in hammering it into the net — and then had to endure taunts of “shoot” from the Liverpool fans every time he touched the ball.
“He’s a strong character, and he will get over that this evening,” Leicester manager Brendan Rodgers said.
“He has come back a little rusty having not played in a long time having got no minutes with Belgium at the World Cup.
“When he came in, he was absolutely fantastic for us and was just unfortunate today.”
It was far from a vintage performance from Jurgen Klopp’s team but Liverpool now have four successive league victories for the first time since April.
“It’s all about getting three points and trying to get into a position in the league where we feel like we need to be and haven’t been this season,” Liverpool defender Trent Alexander Arnold said. “These are the ones that you look back on and know that you needed to win it. Whether you win well or ugly, it doesn’t really matter.”
West Ham would be more than happy to get an ugly win, after outplaying Brentford for large parts of the game and still losing 2-0.
David Moyes’ team are staring at a crisis after a fifth straight loss. The London club could find themselves in last place by the end if the weekend.
The team were booed off the field after first-half goals from Ivan Toney and Josh Dasilva inflicted another damaging loss on Moyes.
“I thought we played well,” Moyes said. “The goals were completely against the run of play, we’ve lost two goals to throw-ins. We made a lot of opportunities, we just couldn’t take them.”
Brentford climbed to ninth, although the win was came at a cost as Toney left on a stretcher in stoppage time after landing awkwardly.
“He had some pain,” Brentford manager Thomas Frank said of Toney, who scored his 13th goal of the season. “It is something with the knee, we hope it is nothing serious.”