Guardiola's side trailed to Harvey Barnes' second-half opener at St James' Park before Ruben Dias equalised for the visitors.

Moments after Dias levelled, Barnes bagged Newcastle's contentious second goal, which was allowed to stand after a lengthy VAR check for a potential offside against Bruno Guimaraes.

Guardiola felt City keeper Gianluigi Donnarumma had been fouled in the build-up to Barnes' winner and was also aggrieved over a rejected first-half penalty claim by Phil Foden.

Guardiola stormed onto the pitch at full-time to confront referee Sam Barrott, but later said "everything is fine" when asked about the incident.

"It happened in the Bournemouth game and it happened today again. It is what it is after VAR decided. They know perfectly," he said with a hint of sarcasm about Newcastle's second goal.

"You see Donnarumma complain and that is because something wrong happened.

"It was an entertaining game, we both had chances and then there was a momentum shift and ultimately we couldn't win."

City's fourth league defeat this season left them in third place, four points behind leaders Arsenal, who host Tottenham on Sunday.

City went into the international break with a 3-0 victory over troubled champions Liverpool that made it seven wins from eight games in all competitions.

But they squandered that momentum in an error-strewn display on Tyneside as Erling Haaland was held without a goal for only the third time in 21 matches for City and Norway this season.

Haaland was hoping to score his 100th league goal in his 109th appearance since arriving from Borussia Dortmund in 2022.

But he wasted several chances and Newcastle took advantage to beat City for just the second time in their last 36 league meetings.

Eddie Howe's first win over City in 19 top-flight attempts eased the pain of Newcastle's successive league defeats at West Ham and Brentford before the international break.

Donnarumma nearly gifted Newcastle the lead inside 30 seconds with a woeful pass that was intercepted by Barnes, but the winger wasted the chance as he shot straight at the Italian from 10 yards.

- Profligate City -

Haaland was guilty of an equally bad miss moments later, scuffing his attempt to chip over Nick Pope after the Newcastle keeper reacted to Jeremy Doku's pass by rashly racing out of his area.

Foden blazed wide from a good position inside the area before appealing in vain for a penalty after Fabian Schar left him writhing in pain with a crunching tackle in the same incident.

Foden and City's coaching staff were furious with the decision, their frustration mounting when Jacob Murphy avoided conceding a spot-kick after blocking Doku's shot with his arm.

In a half of poor finishing, Barnes was guilty of the worst moment when he contrived to shoot wide from close range with the goal at his mercy.

Even Haaland was off the mark, flicking Nico O'Reilly's cross straight at Pope from five yards.

Remarkably, the unmarked Foden produced a worse miss, dragging wide from Rayan Cherki's pass just before half-time.

City finally cracked as Barnes made amends for his earlier misses with a fine finish in the 64th minute, lashing a low drive past Donnarumma from the edge of the area after Guimaraes' run and pass prised open the defence.

Guardiola's men trailed for just four minutes.

Bernardo Silva's shot was blocked towards Dias and the Portugal defender's powerful strike from 12 yards deflected in off Schar.

But Dias's first league goal since he scored at Newcastle four years ago sparked an immediate response from Howe's side.

When Nick Woltemade guided his header across goal, Guimaraes nodded against the bar and the rebound fell to Barnes to volley home.

The long VAR check for offside against Guimaraes seemed to favour City but it eventually went in Newcastle's favour as the Magpies faithful hailed a memorable victory.