Jose Mourinho ordered his critics to take a vow of silence after pulling off a masterstroke substitution in Saturday's 1-0 win against Tottenham at Old Trafford.
Mourinho, stung by the negative reaction to United's recent bore draw against Liverpool, created more discontent among United fans when he took off Marcus Rashford after 70 goalless minutes.
But the Special One had the last laugh when replacement Anthony Martial grabbed the winner with 10 minutes left, and the manager celebrated at full-time by putting his finger to his lips in a gesture that told everyone "I know what I'm doing".