Jesse Lingard scored his fourth goal in as many games and substitute Romelu Lukaku added a stoppage time effort as Manchester United reached the English FA Cup fourth round.
The former champions beat Championship side Derby County 2-0 on Friday.
Lingard, who scored a pair of fine goals in a 2-2 Premier League draw with Burnley, followed by another in a 2-0 win at Everton, produced another exquisite finish this time.
He unleashed a first-time shot from 18 metres in the 83rd minute.
Lingard hit the post several minutes earlier as Derby looked set to earn a reply after United had missed a string of chances.
Marcus Rashford also hit the woodwork while visiting goalkeeper Scott Carson produced a barrage of good saves.
Lukaku, who returned from a head injury and came on as a halftime substitute for Henrikh Mkhitaryan, broke away and powered his shot past Carson at the death.
This came as Derby threw men forward in search of an equaliser.