And visiting boss Jurgen Klopp could be forgiven for struggling to contain that famous toothy grin as he watched his team excel all over the Riverside pitch.
Dejan Lovren marshalled his defence expertly, Jordan Henderson quarter-backed the midfield like the England captain he is, while up-front the pace and slick interchanges of Sadio Mane, Roberto Firmino and Divock Origi troubled the Teessiders all evening.
If the visitors had a weak link it lay at left-back where time appears to be catching up with James Milner’s legs.
Several times he was exposed by the pace of Adama Traore but even then Liverpool were not unduly troubled with a sparking Simon Mignolet returning in goal to remind fans that no matter his occasional high-profile calamities, there are times when the Belgian keeper is complete class.
Both sides made a couple of changes from their previous games.
For Middlesbrough, Traore and fit-again leading scorer Alvaro Negredo returned; for Liverpool, Ragnar Klavan replaced Joel Matip while Mignolet came in for Loris Karius.
Understandably, that last change was the major talking point before kick-off with Klopp having defended Karius’ recent errors all week before dropping him to the bench last night.
The German stopper must have felt hard done by in the early stages — missing out for the chance of a morale-boosting match against the Premier League’s lowest scorers and in the early stages of the game, both side’s keepers were spectators.
Then, on an unseasonably mild night on Teesside, the game began to heat up — Fabio’s long-range shot from the left flank in the 18th minute was a tricky one for Mignolet, the ball skidding on the wet turf before reaching the keeper but he took it well.
Better, much better, was to come from the Belgian.
In the 22nd minute he showed awareness and agility saving the ball at ground level when Boro skipper Ben Gibson headed back and down at the far post Adam Forshaw’s free-kick from the right.
And on the half-hour he produced a superb one-handed block at his near post to deny Adam Forshaw’s thrashed shot which could have gone anywhere.
Seconds earlier, Liverpool made Mignolet’s saves count when they took the lead when Adam Lallana took advantage of a hesitant defence to power home a header at the far post from Origi’s right wing cross.
Middlesbrough were undaunted by dropping behind.
A long-distance, pile-driver from Adam Clayton might have levelled the scores had it not knocked Dejan Lovren off his feet.
And in the 40th minute once again Mignolet was forced into a five save, this time to deny Forshaw from 12 yards.
Liverpool finished the first-half strongly — Mane hitting the post, Origi the side-netting; and they started the second-half strongly too — Mane twice denied by great defending in the 46th and 47th minute.
Those misses were not to prove costly though as Liverpool’s game simply went up through the gears.
They extended their lead just after the hour when a slick interchange of play saw Lallana turn provider, setting up Origi for his fifth goal in fives games.
The big striker returned the favour in the 68th minute when a good interchange with Mane on the right wing ended with the forward rolling the ball across the box and from 12 yards out at the far post Lallana tapped home.
There is so much that is champagne and slick and summery about Liverpool’s stylish play under Klopp when they perform like this, Inevitably then the question was always going to be asked: yes, but can they do it on a December night in Middlesbrough?
Yes they can.
(4-3-3) Valdes 6; Da Silva 6, Gibson 6, Chambers 5, Barragan 5; de Roon 5, Forshaw 6, Clayton 5(sub Leadbitter 55, 5); Fischer 5 (sub Downing 55, 6), Traore 7, Negredo 5 (sub Rhodes 5). Subs not used: Guzan, Bernardo, Nsue, Nugent.
(4-3-2-1) Mignolet 8; Clyne 6, Lovren 7, Klavan 6, Milner 5; Henderson 7, Wijnaldum 6 (sub Ejaria 86, 6), Lallana 9 (sub Leiva 81 ,6); Firmino 7, Mane 7; Origi 7 (sub Alexandar-Arnold 91). Subs not used: Karius, Moreno, Stewart, Woodburn.
Jon Moss (West Yorkshire).