Romelu Lukaku's first-half brace put the Red Devils up 2-0 at the break—Alexis Sanchez crossed in for the Belgian to head in his first before dispatching a much scrappier second in the 44th minute. Joe Hart denied Paul Pogba from the penalty spot in the second half to keep the deficit down to two goals.
United's second win of the campaign has pushed them back into the top half of the table and level on points with Unai Emery's Arsenal, who scored late to snatch a 3-2 win at Cardiff City earlier on Sunday.
Lukaku Must Show More After Burnley Brace If He's to Be United's Saviour
It seems harsh to find room for improvement in a striker's performance immediately after tripling his goal tally for the season, but Lukaku's second and third goals of the season don't offer him absolution just yet.
Scoring in batches was a lot more regular for the frontman during his days at Everton, and Sky Sports Statto attested to his Turf Moor double ending a run of single-scoring in the league:
But against a beleaguered Burnley, who only last week saw their UEFA Europa League qualification hopes ended by Olympiakos, United should have been seeking more.
Lukaku's goals were relatively routine when looking back. His first set up by a superbly swung Sanchez cross, and his second an awkward poke home from close range after it looked as though the chance had gone astray.
Had United's leading scorer been even more attentive in front of goal, United could have had five at Turf Moor, but the win will mask over most shortcomings, particularly as Lukaku managed a major individual feat, per Squawka:
Lukaku's few clinical moments had their effect on a Burnley team that took its time to get going. He looked strong with his back to their defenders and offered a positive passing point but little else in terms of running in behind or moments to lift the crowd.
Instead, there were other instances that might have served to justify his status as a world-class finisher. Such as the one-on-one chance after 79 minutes in which he bamboozled himself into giving the hosts a goal kick, or the opportunity Joe Hart saved from his minutes earlier.
These are the chances preventing United from wrecking teams as viciously as they once did. And while Lukaku may have as many Premier League goals as Chelsea great Didier Drogba, there is work to be done before he's a star of the same calibre.
Rashford's Red a Natural By-Product of United Frustrations
It would be wrong to spin Marcus Rashford's deserved red card on Sunday as explicitly caused by a lack of playing time, but his out-of-character lashing out at Phil Bardsley for a bad tackle is indicative of a frustrated persona.
Only 10 minutes after he entered the fray with his side leading 2-0, Rashford fought for a ball that drew a poor tackle out of Bardsley, and he wasn't afraid to make his dissatisfaction known, via Sky Sports (UK only):
The 20-year-old returned from the 2018 FIFA World Cup and was a second-half substitute for the second time in as many United appearances at Burnley, though this one was short-lived.
Having only picked up six yellow cards in 80 top-flight appearances, Rashford's first career red card also ended a good run of discipline among United's subs, per OptaJoe:
BBC Sport's Simon Stone noted the Red Devils' upcoming fixture list following Rashford's rush of blood to the head:
Sanchez's return to productivity doesn't bode well for Rashford in terms of his attacking prospects, with Lukaku already governing the central striking reserve, while Anthony Martial still has his supporters.
It's difficult to know how things improve swiftly for Rashford other than Jose Mourinho agreeing to rotate more economically between him and Lukaku, which seems highly unlikely given the trust he has in the Belgian.
Mourinho Must Settle on Defence After Fielding Third Centre-Back Pairing
A first clean sheet of the season bodes well for United's defence moving forward, but there are still questions to be asked in defence after what was always likely to be one of the club's easier opening fixtures, namely at centre-back.
The starting pair of Victor Lindelof and Chris Smalling was the third combination Mourinho has tried in four league games this term, and the changing faces wasn't missed by actor Harshvardhan Kapoor:
The indecision in central defence continued as Eric Bailly, seen by many as the best defender at Mourinho's disposal, was benched at Burnley, though this time with the desired effect.
Samuel Luckhurst of the Manchester Evening News agreed there appeared to be some harmony between Lindelof and Smalling:
But there are much bigger tests to come that may rule Sunday's performance largely irrelevant. Chris Wood started alone in attack after coming on in last week's draw against Olympiakos but was muted for most.
In fact, it was after the Clarets added a second striker that writer Simon Evans remarked a change in tempo:
After Burnley's busy schedule of late, Sean Dyche's side were never going to pose the stiffest contest even at Turf Moor, though Smalling and Lindelof will also benefit greatly from the boost in confidence.
United's failure to sign a star centre-back over the summer is once again raising its head as a concern, with the question being whether Mourinho has yet settled on his best pair or if the experimentation is set to continue.
Life on the road continues for Manchester United after the international break as they prepare for a trip to Watford on Saturday, September 15, the day before Burnley are back in action at Wolverhampton Wanderers.