Ryan Gravenberch benefited from an error by Union Saint-Gilloise goalkeeper Anthony Moris to score his first goal for the club as Liverpool laboured to a 2-0 Europa League victory to maintain their 100 per cent record in Group E.
For all the attacking firepower at their disposal – and it was considerable with Mohamed Salah, Darwin Nunez and Diogo Jota boasting 248 goals between them – it was a 21-year-old former Ajax and Bayern Munich midfielder who had scored just nine in five years who popped up with the breakthrough at a crucial moment a minute before half-time.
That two of the front three were replaced at the interval was more down to a prepared plan rather than a reflection of their first-half contributions but if either had been anywhere close to their sharpest the game would have been out of sight before Gravenberch's intervention.
Jota remained on for the whole game and scored the second with a breakaway in added time to ease any late nerves.
Salah's first Europa League start for the club would have led to speculation about just how much devastation he could inflict, especially after his 16-minute cameo in their first European game produced a goal, an assist and a couple of other chances.
In his 150th game at Anfield he should have added to the 103 he has scored already on this ground as early as the fifth minute.
The excellent young centre-back Jarrell Quansah, deputising for rested captain Virgil van Dijk, won the ball high in midfield and released the Egypt international through the middle but he could not beat the goalkeeper.
It was the beginning of a long list of chances ultimately concluded by Gravenberch's close-range effort and while Liverpool never looked in any real danger after Gustaf Nilsson had headed over Union's best midway through the first half until the latter stages the game was more of a grind than it should have been.
Nunez's 10th-minute rebound goal from Gravenberch's shot was flagged offside and, on this occasion, UEFA's VAR officials swiftly made the correct call.
A video replay only increased the Uruguay international's embarrassment with his next effort, however, as he screwed wide from six yards having opted to go with his right instead of left foot for Salah's cross after Harvey Elliott had carried ball effortless through the Union midfield.
A weak Salah header straight at the goalkeeper, a Jota penalty claim turned down and a Nunez shot tipped around the near post from Ibrahima Konate's diagonal pass all followed as chances came and went.
After all just about withstanding all that in-your-face pressure Union were undone from their own attacking corner as captain-for-the-night Trent Alexander-Arnold broke down the left, cut inside on his right foot and drilled in a low shot which bounced in front of Moris.
It was not the most vicious of strikes and the Luxembourg international should have done better than to spill the ball a couple of yards in front of him.
It was all the encouragement Gravenberch needed and he popped home the rebound from close range.
A triple half-time substitution brought an end to the participation of the misfiring Salah and Nunez and also midfielder Wataru Endo as Jurgen Klopp sent on Luis Diaz, Curtis Jones and Alexis Mac Allister – who was made to wait 45 minutes to face his brother Kevin in the opposition defence.
After an early scare when Alisson Becker missed his punch at a corner and almost turned the ball into his own net only for Quansah to sweep up behind him.
Moris tipped over a Jota header and did even better denying Gravenberch a second from a curling shot and even when he was beaten by Diaz his left-hand post came to his aid, while Jones narrowly missed the target with a low shot.
Jota's goal made the game safe and victory over Toulouse, two points behind, at Anfield in three weeks will go a long way to securing qualification to the knockout stages but Liverpool cannot afford to be so sloppy if they want to enjoy comfortable progress.
