Matheus Nunes scored his first Manchester City goal in his 34th appearance as the hosts eased to a 2-1 victory over second-tier Watford to reach the fourth round of the League Cup on Tuesday.
Jeremy Doku slotted in City's opener after five minutes and Nunes produced a clinical finish in the 38th minute to put Pep Guardiola's side in control at The Etihad.
Watford have suffered some horrible Premier League maulings against City in recent seasons but they refused to capitulate and Tom Ince gave them an 86th-minute lifeline with a curler.
Eight-time winners City avoided being dragged in to a penalty shootout though despite some late Watford pressure.
City were back in action little more than 48 hours after their seismic clash with Arsenal in the Premier League and Guardiola rotated his squad with several regulars rested, handing a first start to 16-year-old Kaden Braithwaite.
His low finish from just outside the penalty area was superb and he could have had a hat-trick but for good saves in the second half by Watford keeper Jonathan Bond.
Watford had begun badly with a poor back pass by Ryan Porteous intercepted by James McAtee before Jack Grealish squared for Doku to spin and tuck away a fine finish.
The visitors had conceded 26 goals in their last five clashes against City, including an 8-0 drubbing in the Premier League in 2019 but proved more resilient this time.
They had a goal ruled out in the first half when Kwadwo Baah was adjudged to have barged over Braithwaite before shooting past Stefan Ortega. But they got their reward late on when Ince finished off a fine move with a left-foot stunner.