But they exacted their revenge with a 4-3 win at Anfield in January, which remains City's only English Premier League defeat of the season. It remains the only league defeat City have suffered so far this season.
The Reds then completed the comeback when Salah scored his 29th Premier League goal of the season.
It was a freaky day for Liverpool's Senegalese superstar, who was booked for diving, had a goal ruled out due to offside, scored for real, picked the ball up after he thought he was fouled and then was hauled off by Klopp before the referee sent him off first.
Jurgen Klopp has been adamant that the former Roma man will not be sold in the summer, with rumours suggesting that Liverpool are preparing an enormous contract improvement to keep him happy at the club. We know it's hard.
Following Liverpool's 2-1 win at Crystal Palace, Klopp said: "Did we think before the first game we would lose 5-0? No. Every point is vital because we want to stay in second place", United manager Jose Mourinho said. But do we know we have a chance? Yes, that was clear before.
'They are capable of winning the league, I'm firmly believe that they are, ' Adam added. No problem with respecting that, but we all know, in this game, it doesn't mean too much. But you can see he has quite clearly flicked the ball away from both [Andros] Townsend and [Yohan] Cabaye, who would have had a chance to advance on goal.
The match looked to be heading for a draw but Premier League's top scorer Mo Salah received a cross from Robertson and beats arriving Sahko before finishing in style.
Liverpool's Adam Lallana is substituted off after sustaining an injury.
Salah is five goals ahead of Tottenham Hotspur sharpshooter Harry Kane as he seeks to emulate Drogba and finish as the Premier League leading scorer.
That's according to BBC Sport pundit Garth Crooks.
"I almost had a heart attack [when he took it]", Klopp added.
But in 49th minute, Liverpool pulled one back. "If you deliver in a situation like this, this is what can happen to you".
"The best thing was how Egypt celebrated getting the penalty", Klopp told The Independent. It was something I never saw in my life. He was still a shoo-in to go to the upcoming World Cup, though, but now that dream may be over.
So it was not a penalty then? "That was real pressure".