Erik ten Hag said Manchester United must be more ruthless after Marcus Rashford struck twice late to send them into the Carabao Cup semi-finals.
United were leading through a first-half Antony strike, but with League One Charlton pushing for an equaliser, Rashford struck in the 90th and 94th minutes to seal the tie.
The win put United into the semi-finals for the third time in four years, but Ten Hag said his players needed to be more clinical, ahead of Saturday's derby against Manchester City.