This Manchester City demolition of Sporting was akin to a heavyweight bullying a featherweight. A fair question was to wonder how these opponents shared the same pitch, so dominant were England’s champions.

At the break Pep Guardiola’s men were four goals up, by the final whistle it was 5-0, and at the close of the tie they may go close to Bayern Munich’s 12-1 evisceration of Sporting at the same stage in 2008-09.

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That was the Portuguese club’s only previous last-16 experience and this lack of knowhow was written all over how City toyed with them and landed killer blows at will. A prime factor is, of course, the riches the side fuelled by Abu Dhabi’s petro‑dollars enjoy: that should allow them to beat a significantly lower‑budget operation such as Sporting but so immaculately are they drilled by their manager, who might stop the City juggernaut finally claiming the Champions League this term is a puzzle.

At kick-off the Estádio José Alvalade glittered from phone torches that lit up the Lisbon night and what followed was a perfect City start. Aymeric Laporte found the excellent Bernardo Silva and, when Phil Foden’s shot was subsequently saved, Kevin De Bruyne passed to Riyad Mahrez and the Algerian scored. City seemed to think De Bruyne was offside but VAR ruled Gonçalo Inácio played the Belgian on, so Mahrez had a 10th goal in his past 11 Champions League appearances.

Sporting and their support were stunned. The Portuguese champions’ last outing, a 2-2 draw with Porto on Friday, ended in a mass brawl and three of their men sent off. In Rúben Amorim they have a 37-year-old manager who cost the club €10m to prise from Braga and whose repayment was a cup-and-championship double, the latter a first title in 19 years.

Amorim now, somehow, had to rally his men but instead City struck again. This time a Mahrez corner was weakly cleared and Silva pounced, rifling a superb half-volley past Antonio Adán for a 2-0 lead 17 minutes in.

Guardiola’s XI featured four old boys of Sporting’s crosstown rivals Benfica – João Cancelo, Rúben Dias, Silva and Ederson were booed initially whenever they took a touch before the home support switched focus to their own team. For a while Sporting showed in flashes. A Ricardo Esgaio raid along the left had City back-pedalling. Then, Pablo Sarabia looked to do the same but the No 17 ran infield and John Stones ended the threat. In between, Pedro Gonçalves, the scorer of four goals in the group stage, let fly twice.

Guardiola, on the prowl in the technical area, was conscious of Sporting’s threat – a volley he gave Dias for not passing diagonally indicative of his concern. The Catalan was about to applaud his team, though. At first Dias, Rodri and Stones played keep-ball in their half. Then suddenly De Bruyne was marauding towards goal, feeding Mahrez who pirouetted and crossed for Foden to finish – Sebastián Coates, the nearest defender, making it too simple for the forward.

Three-nil up so soon pointed to the serious mismatch occurring. City were illustrating precisely why they are the competition favourites and Sporting were showing how Ajax put five past them here in September. The rest of the period had City in a quasi-exhibition mode. Passes were interchanged, positions shifted, differing zones occupied. And, then, a fourth was secured: this time Silva’s strike was from close range, Raheem Sterling teeing him up.

City’s travelling contingent ended the first half regaling their team. The second half, now, seemed a matter of how many more they might register.

Sporting fans, to their credit, kept singing and would do so until the end.

The way Cancelo, De Bruyne and Rodri harried their men showed City were targeting the jugular still. On the touchline Guardiola next threw up his hands in dismay at an errant Dias chip forward, then had a prolonged chat with the fourth official, his gestures suggesting unhappiness with the refereeing of Srdjan Jovanovic.

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More pleasing for the 51-year-old was how a rare Sporting attack was broken up and City, in their slick fashion, moved upfield via Rodri, De Bruyne and Cancelo. And, even better was the team’s fifth finish. Here, Sterling was ruthless, the No 7’s long-range effort sailing into the top corner and moving him to 10th on the club’s all-time list of scorers.

This had entered embarrassing territory for Sporting. Portugal’s domestic champions were being made to appear a part-time outfit. There were no more goals – but only because City were content with their night’s work.

Guardiola found fault with the “loss of balls” as he is a perfectionist. But, he did also call it, correctly, the “dream result”. Silva, the clear man-of-the-match, said: “It was nice to start the last 16 with a 5-0 win. There is still a job to do in Manchester. We cannot relax.” They most certainly can.