The defending Premier League and Champions League champions controlled the first half but failed to score.
In the dying moments of the game, Rico Lewis came agonizingly near, dragging his shot just wide of Nick Pope’s left-hand post.
But for the team that Southampton eliminated in the quarterfinals last year, it turned out to be a discouraging evening.
Following the swift series of fouls committed by Manuel Akanji and Kalvin Phillips in the second half, Guardiola also received a booking after letting his temper flare.
As Newcastle terminated their chances of recovering the Carabao Cup in the second half, fans on social media had one word to describe City’s performance: rattled.
Newcastle are in control and Manchester City need adjustments because they appeared rattled, according to one.
Added another: “City are rattled.”
At St. James, Man City was utterly shaken. Another added that Newcastle had demonstrated to the league how to unsettle them.