Ashley Young cut in to provide a stunning breakthrough for the hosts, and Juan Mata found space in the box to create a two-goal cushion. Romelu Lukaku poked in from short range to make it 3-0 at half-time. Marcus Rashford helped set up two before drilling in a long-range strike of his own in the 82nd minute.
Aboubakar Kamara converted a controversial penalty in the second half after going down under pressure from Ander Herrera, but Andre-Frank Zambo Anguissa's red card a minute later ended any hopes of a comeback.
Lukaku's Still 'The Man' for United's Big Games
Lukaku's lacklustre form this season led to him being dropped from the XI in recent games against Arsenal and Young Boys, but his omission should be short-lived after underlining his value as Mourinho's focal point on Saturday.
His first-half strike from a Mata cut across goal was much-needed, too, after Lukaku had endured an Old Trafford scoring drought that few would have expected of the £75 million man:
Lukaku also missed out on a starting spot against Manchester City in November but was recovering from injury at the time. His omission against the Gunners on Wednesday was a clearer statement that he was missing form.
After a run of 12 games without a goal, Lukaku now has two in his last two league starts and is sure to benefit from alleviating the pressure of his wait for a home goal.
Rashford and Anthony Martial impressed alongside one another at times against Arsenal, but there's no doubting the benefits of Lukaku playing with confidence, something we're seeing more of in recent outings.
That being said, Fulham are the bottom team in the Premier League for a reason and have the worst defence in the division, leading Men In Blazers to hint Lukaku's contribution may have been more down to the visitors:
Lukaku's ball in to Rashford to help set up Mata's strike showed he can be the composed hold-up specialist at higher speeds, and he managed to hit the target with three of his four shots, per WhoScored.com. That's evidence of more attacking intent considering his average prior to Saturday was 1.6 shots per game.
The upcoming trip to Valencia in the UEFA Champions League on Tuesday, followed by Sunday's Premier League clash against title hopefuls Liverpool, are somewhat daunting given the recent unrest at United.
However, after a warning period out of the team, Lukaku looked refreshed against Fulham and ready to reiterate his importance as the world-class leading man Mourinho has long sought.
Assist King Rashford Still Far From the Finished Product
One goal and two assists is an extremely healthy contribution for any winger, but Rashford's input on Saturday stood as an example of how statistics can sometimes be misleading.
His first assist was a roll wide to Young, who did all the hard work with his curl inside the far post.
The second was a better illustration of his supplementary talents, per Statman Dave:
It was fair reward for a 21-year-old star who's at times been under undue pressure this season and criticised for missing chances when deployed up front.
Yet despite his assist notches on the board, Rashford still looked out of sorts on the left flank at times, almost as though caught between his positioning out wide and his natural instinct to drift closer to goal.
He and Lukaku interchanged roles at times to good effect, and other times less so:
Rashford's goal was a thing of opportunistic wonder, the likes of which he first became adored for when he burst into United's senior squad.
But again, journalist Kris Voakes noted how goalkeeper Sergio Rico was perhaps generous:
Defences of higher quality won't concede the same strikes, and while Rashford deserved credit for the initiative, supporters need not expect this to be the beginning of a new trend or surge.
That being said, the speedster can only play what's in front of him, and there were times where he looked every bit a natural winger:
For the time being, Rashford can look to fixtures such as these to hone his obvious skills and develop confidence, but there were times where he showed why Mourinho may be justified rotating his homegrown starlet.
The Red Devils have only three days turnaround before they travel to Valencia for their final UEFA Champions League group game on Wednesday, while Fulham aren't back in action until they host West Ham United in the Premier League on Saturday.