Liverpool survived a major scare from Aston Villa's youngsters before claiming their place in the FA Cup fourth round with a 4-1 victory.
Forced to name a starting XI comprised entirely of players without a first-team appearance to their name as a result of a COVID-19 outbreak, the Villans produced a hugely impressive performance under the guidance of U23s boss Mark Delaney.
It was enough to see them deservedly level at the break, Louie Barry finishing off a well-worked move to cancel out Sadio Mane's early header.
But Georginio Wijnaldum's strike on the hour-mark served to break the kids' resistance and was followed by further goals from Mane and Mohamed Salah that added gloss to the scoreline.
Villa would have been anticipating a long night ahead when Mane headed home Curtis Jones' right-wing cross with just four minutes on the clock.
Only two great stops in quick succession from Akos Onodi stopped the Reds doubling their lead soon after, the young goalkeeper keeping out Fabinho's low shot before rising to save Mane's follow-up.
But, while they continued to dominate possession as the half wore on, Liverpool hardly had the Villa goal under siege, and they paid the price as the hosts made the most of their first real attack.
Callum Rowe did brilliantly to evade Jordan Henderson deep in midfield before sliding an inch-perfect pass through to Barry, who saw off the challenge of Rhys Williams and produced a composed one-on-one finish that belied his tender years.
Liverpool could not have expected to find themselves in such a battle at Villa Park but responded with renewed vigour following the restart.
The pressure finally told on the hour, Wijnaldum sidefooting home in space with tired Villa legs unable to close him down, and two further goals in the next five minutes put the game to bed.
The first came from Mane, who looped a header up and into the far corner, before Salah got in on the act with a low finish into the corner.
What does it mean? More cause for Klopp concern
While Villa's youngsters will receive deserved praise for their first-half heroics, the opening 45 minutes cannot have been an easy watch for Jurgen Klopp.
Liverpool came into this game having failed to win in their last three outings and their struggles continued for large periods against inexperienced opponents who looked there for the taking after conceding early.
If the Reds are to get their season back on track, they are going to have to find improvement from somewhere.
Revan a rock for Villa
Although he would have been excited at the prospect of coming up against this Liverpool attack, Dominic Revan surely could not have expected to fare this well.
The 20-year-old was hugely impressive for the hosts, making 14 clearances – more than anyone else on the pitch – and winning 66.7 per cent of his duels up against some world-class attackers.
Although his half-time substitution had all the hallmarks of a planned change, Henderson was far from at his best at Villa Park.
The captain was too easily beaten to the ball in the moments before the hosts' goal, lost possession on 10 separate occasions with some aimless passing, and failed to make a single tackle in his 45 minutes on the pitch.
Key Opta facts
- Aston Villa's starting XI average age was just 18 years and 294 days – there had not been a player aged as young as that in any of their last 158 line-ups in all competitions, not since Jake Doyle-Hayes started against Middlesbrough in September 2017 aged 18 years and 263 days.
- Five of Villa's starting XI (Kaine Kesler, Louie Barry, Lamar Bogarde, Benjamin Chrisene, Mamadou Sylla) were not even born when James Milner made his first ever FA Cup appearance, in January 2003 for Leeds United against Scunthorpe United.
- Xherdan Shaqiri became the first Liverpool substitute to assist two goals in a single game since Milner in December 2017 against Spartak Moscow (3), the Switzerland international getting his brace within 208 seconds of coming off the bench.
- Barry (17y 201d) became the youngest player to score an FA Cup goal for a Premier League club since Rony Lopes (17y 8d) for Manchester City against Watford in January 2013.
- Barry (born June 2003) is only the second player born in 2003 to score a goal for a Premier League club, after Liam Delap (born February 2003) for Man City against Bournemouth in the EFL Cup earlier this season.
Liverpool now have a rare nine-day gap before facing bitter rivals Manchester United in a top-of-the-table Premier League clash. It remains to be seen whether Villa will be able to fulfil their next scheduled fixture, a league encounter with Tottenham on Wednesday.