The visitors’ recent woes prompted a change in goal from Guardiola, who dropped Ederson to the bench in favour of Stefan Ortega.
The German was busy in the opening stages as City faced a barrage of Liverpool attacks, denying a pair of Dominik Szoboszlai efforts before the Hungarian turned provider for Virgil van Dijk, who headed against the post.
There was a sense of inevitability about the opening goal arriving, and as has been the norm at Anfield down the years, a piece of genius from Mohamed Salah provided it.
The Egyptian produced a pinpoint ball across the City goal, with Cody Gakpo arriving at the back post to bundle home in front of the Kop.
City’s insistence on playing out from the back kept landing them in trouble even after falling behind, with Van Dijk heading another big chance wide before Gakpo fired over the bar.
Guardiola’s men at least stemmed the flow of attacks from there, but creating anything in their search for an equaliser was a different story.
Not until the 39th minute did the visitors manufacture a shot of any description as Rico Lewis tamely missed the target to sum up another half of misery for the champions.
It’s the longest City have had to wait for their first shot of a PL match since April 2010, and though they looked a more dangerous outfit following the restart, it was still Liverpool creating all the chances.
Gakpo saw a shot blocked by the retreating Matheus Nunes, while Van Dijk headed yet another opening over the bar.
The biggest miss belonged to Salah, who pounced on a loose pass from Bernardo Silva to go through on goal, but the Egyptian lifted his chance over the bar.
All that was missing from the hosts’ performance was a second goal to kill the contest, and 12 minutes from time they got what they deserved.
After Ruben Dias was caught in possession, Luis Diaz raced through on goal only to be felled by Ortega, allowing Salah to step up and slot home from the penalty spot, atoning for his miss against Real Madrid in midweek while directly contributing to his 13th goal in his last 11 starts against the Citizens.
Arne Slot’s men have now beaten the champions of England, Spain and Germany at Anfield this season and sit a commanding nine points clear of Arsenal at the PL summit.
City, meanwhile, sit outside the top-four after losing a fourth league game in succession for the first time since August 2008.