Darwin Nunez’s first half-strike was the difference between the two sides on the night, but the Reds were made to sweat during the nervy final stages in Germany.
Benjamin Seso and Xavi Simons had great chances for RB Leipzig but were denied expertly by Kelleher in the Liverpool goal.
The Republic of Ireland international has often played second fiddle to Alisson throughout his Anfield career but started his second successive game with the Brazilian out with a hamstring injury.
And his display on Wednesday night was praised by Ferdinand and Steve McManaman at full-time, with both impressed at how quickly he has got up to speed having spent the first portion of the season on the subs bench.
‘Keepers don’t come in often but when they do you want them to come in and hit the ground running,’ Ferdinand said on TNT Sports.
‘They haven’t got time to get settled, they’ve got to be able to take up the pace of the game and get in the grove immediately.
‘Every time I’ve seen him he’s done really well in that sense. Alisson has got big shoes to fill but he comes in and it just looks effortless with him.
‘You have to have a level of humility to be able to go “I am this guy” and sit in the background for the majority of the time but when called upon you’ve got the confidence to come in and perform.’
McManaman added: ‘It’s almost disrespectful saying he’s a number two because, of course, he does play second in command when Alisson is fit but he’s played too many games to be associated with that [label]. He’s an outstanding goalkeeper when called upon.’
Liverpool boss Slot was equally keen to sign Kelleher’s praises at full-time.
‘Very fortunate [to have him],’the Dutchman said. ‘It’s also a normal thing at a club like ours that you have very good players in every position.
‘Ali was out last season and out this season again. It’s not only him. We have players who are not always in the starting lineup who did it again today.’
Kelleher will need to be at his best again on Sunday when Liverpool travel to the Emirates to take on Arsenal in the Premier League.
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