Liverpool captain Steven Gerrard's penalty gave his side a 1-0 advantage after the first leg of their Carling Cup semi-final against Manchester City at the Etihad Stadium.
The England international slotted home his fourth goal of the season after the hapless Stefan Savic had fouled Daniel Agger in the 13th minute.
City, missing key trio Vincent Kompany, David Silva and Yaya Toure, suffered back-to-back home defeats for the first time since February 2008 having lost to Manchester United in the FA Cup at the weekend.
After the game Gerrard rejected Roberto Mancini's criticism of a tackle by Glen Johnson during the match.
The City boss, whose side were without Kompany due to his red card for a two-footed challenge on Nani at the weekend, said felt Johnson should have suffered similar punishment for a foul on Joleon Lescott
In the aftermath of the FA Cup clash with United, Mancini claimed that United's Wayne Rooney had tried to influence the Kompany sending-off.
Gerrard told BBC1: "It surprises me because he had a go at Wayne Rooney. Now he has had a go at one of ours."
But Gerrard warned his team-mates not to take a place in the final for granted.
He said: "There is no way this game is over, the job is half done."
Mancini admitted referee Lee Mason had been right to award the penalty but insisted he should have punished Johnson for sliding in two-footed on Lescott.
"I want to see the tackle by Johnson. I thought that was worse," he told BBC1.
Mancini admitted the absence of Kompany through suspension, David Silva with an ankle injury and with Yaya and Kolo Toure at the African Nations Cup, had made it hard for his team.
He said: "It is clear that without three or four players it's difficult.
"The result is not right. For me the result was a draw maybe."
