Jesse Lingard and Anthony Martial struck in the first half and Wayne Rooney was on target after the interval, keeping United in the hunt for a top-four finish and easing the pressure on manager Louis van Gaal.
"It was a great first half, we scored fantastic goals and we created more chances above that," the 64-year old Dutchman, whose side had not managed a first-half goal in their previous 11 matches at old Trafford, told Sky Sports.
"In the second we controlled the game, scored the third goal. It was very good."
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"Three goals eh? In a row!"
In line with the adventurous philosophy which spurred United to win a huge haul of trophies under former manager Alex Ferguson, they finally reverted to the attacking football that had been missing under Van Gaal.
Having picked either one or the other for most of the season, the former Barcelona boss started with Lingard and Juan Mata after fielding them in Friday's impressive 3-1 FA Cup fourth round win at Derby County.
The pair's crisp passing again created space for Rooney and Martial to exploit and allowed fit-again Michael Carrick to boss the centre of midfield.
United's domination was rewarded when Cameron Borthwick-Jackson celebrated his 19th birthday by unleashing a teasing cross for Lingard to head home from close range.
Martial doubled their lead midway through the opening period with a delightful shot from the edge of the penalty area after Rooney found him with a clever crossfield pass.
The England striker had a goal disallowed for a foul on Glen Johnson shortly after the break but there was nothing wrong with his tap-in several minutes later, which came after United's most impressive move of the match.
Mata, who probed the visiting defence all night, released Martial and the French youngster squared the ball to Rooney for a simple finish.
"We were on top, we were sharp and that's what we needed to do today," Lingard told BBC Sport.
"A result like that settles the nerves of the fans, the players, even the manager."
Van Gaal's and United's credentials will come under scrutiny on Saturday when they visit champions Chelsea.
(Writing by Zoran Milosavljevic, editing by Pritha Sarkar and Martyn Herman)
