Rayan Cherki for Tijjani Reijnders was the only change made by Guardiola, and the 22-year-old was soon in the thick of it, with a shot off target as the hosts looked to press home an early advantage.
Man City on the front foot
Regis Le Bris' Black Cats have been winning plaudits all season long for the way in which they've been playing, but they were hemmed into their own defensive third in the opening 15 minutes.
40.6% of play had been in and around their penalty box, with City enjoying a huge 77% possession.
Enzo Le Fee's shot in the 16th minute was the first by any visiting player, and allowed the Sunderland defence some brief respite from an onslaught which continued when Phil Foden had two more efforts at goal in quick succession.
Cherki continued to be the brightest spark on a dull Manchester day and provided the assist for Ruben Dias to slam home a stunning long-range effort that gave Robin Roefs no chance.
Gvardiol makes it two
A fourth assist of the season for the wide man underscored Guardiola's decision to start him, and City's 17th first-half goal in 25/26 was more than any other English top-flight team had managed so far in the current campaign.
It was soon 18 as Josko Gvardiol rose powerfully to head home from Foden's pinpoint corner kick, the fourth game in a row that the Englishman has either scored himself or assisted for a teammate.
Foden certainly appears back in the groove again after a barren period, and his work rate was notable on the day too, as he involved himself in six separate one-on-one duels and had the second most touches in the Sunderland box (seven).
The visitors had been completely overrun in the first half, even resorting to 10 men behind the ball at one stage. A collective 36.1% possession had to be one of their lowest outputs of the season so far, and not having a single shot on target before the break was therefore no surprise at all.
Same pattern emerges
Their inability to find the net in the opening 45 has become something of a thorny issue for Le Bris, too, given that only Nottingham Forest's 11 games (from 15) without scoring before the break is worse than Sunderland's 10.
The same pattern continued in the second half, and four shots in two minutes from the hosts also saw a brilliant Jeremy Doku effort come back off the post.
Doku had been causing problems all game long for Sunderland's back line, both with his pace and a 93.1% pass completion. Not bad when one considers that the visitors attempted to double up on him for much of the game.
Not since facing Bournemouth on 4th November 2023 had he created five chances in a match either.
Cherki's rabona assist
Stretching the pitch was key for City, as they were able to pull Sunderland's players out of more congested central areas, which in turn opened up space for Nico Gonzalez and Bernardo Silva to work.
Wilson Isodor finally had the visitors' first (and only) effort on target on 52 minutes, and this was swiftly followed by Granit Xhaka rattling the post in what was the only real spell of danger from the Black Cats.
Xhaka could at least be relatively satisfied with his own performance, which, as might be expected, was full of grit and determination.
Erling Haaland's 57th shot of the season - more than any other player - was scrambled off the line, before Cherki's insane rabona assist found an airborne Foden to head home the third and make the game safe.
Trai Hume; a ray of light amongst the gloom
A flurry of late substitutions did little to alter the course of the game, and to top off the Wearsiders' afternoon, Luke O'Nien received a red card for serious foul play in stoppage time.
When poring over the reasons why his side were so comprehensively undone at the Etihad Stadium, Le Bris may want to take a look at just how many times his players gave up possession.
For example, Nordi Mukiele and Enzo Le Fee between them lost the ball on an astonishing 23 separate occasions. That's not good enough against any team, let alone against one who will almost certainly always punish the error.
It made the efforts of Trai Hume - seven duels won from nine contested, and three successful tackles from five attempted in an all-action performance - inconsequential.
Seven touches in the City penalty area compared to 42 from the hosts at the opposite end of the pitch, and an appalling collective pass completion of just 58.2% in the final third, would also indicate that, on the day, there was little Sunderland could do to stop the City juggernaut from rolling on.
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