Bruno Fernandes scored an opening-day hat-trick as Manchester United swept Leeds aside with a devastating second-half display.
The Portugal midfielder opened the scoring on the half-hour mark at a packed Old Trafford, but Luke Ayling's thunderous strike drew Leeds level early in the second half.
Mason Greenwood restored the hosts' lead with a crisp finish less than two minutes later, before Fernandes' low shot was ruled to have crossed the line by referee Paul Tierney after a check of goalline technology.
The 26-year-old quickly completed his hat-trick with a thumping finish from Victor Lindelof's pass, before Fred added United's fourth goal in 14 minutes from Paul Pogba's cross - the Frenchman's fourth assist of the afternoon.
It was Fernandes' first hat-trick since he moved to Old Trafford in January 2020 and only the second by a Red Devils player since Robin van Persie's title-winning effort against Aston Villa in 2013.
But the game was also a personal triumph for Pogba.
The France midfielder's future has been the subject of intense debate as he enters the final year of his contract.
But his four assists included a sublime pass for Greenwood's goal, and he left the field to a standing ovation 15 minutes from time as £74m new-boy Jadon Sancho was introduced for his debut.
Bravo Bruno
Fernandes' last hat-trick was for Sporting Lisbon in an 8-1 hammering of Belenenses in front of just over 5,000 in May 2019.
Although the Portuguese has assumed hero status since moving to England, this was only the fourth time he had played a Premier League game in front of capacity crowd at Old Trafford.
After a disappointing Euro 2020, any concerns about his impact at domestic level have been completely dispelled.
His opener was excellent as he ran on to Pogba's first-time pass, controlled a bouncing ball in the Leeds area, then put enough power into his shot to take it into the net despite Illan Meslier's half-save.
Another Pogba pass offered Fernandes the opportunity to sit Meslier on his backside as he turned sharply before hitting a low shot goalwards that referee Tierney was correctly informed had crossed the line before Ayling cleared.
Fernandes' third was route one. Lindelof's pass fell perfectly for the forward, who allowed the ball to bounce before crashing it into the net.
It meant he followed Anthony Martial as the only Manchester United player to score a Premier League hat-trick since Van Persie - and the first to do it in front of fans.
Leeds swept away
The volume for an already noisy crowd was turned up another notch by Raphael Varane's introduction just before the teams emerged.
Manchester United's new £34m defender will be tasked with bringing greater stability to a back four that, even here, looked shaky at times.
Skipper Harry Maguire was almost embarrassed in a foot race with Patrick Bamford which he started with a clear advantage and poor marking should have been exploited by Rodrigo, who was off target with his header after being allowed to meet Raphinha's curling free-kick unopposed.
For a team whose league record at Old Trafford is poor - Leeds have not won here since 1981 - and who conceded six in the corresponding fixture last season, it did not bode well.
Ayling did offer some hope when he was afforded far too much space to shoot - presumably on the basis he had never previously scored a Premier League goal - and promptly found the corner from 25 yards.
But it was only the prelude to a Manchester United onslaught from which there was no chance of recovery.
More to follow.
Player of the match
Bruno FernandesBruno Fernandes
Leeds United
Squad number2Player nameAyling
Squad number1Player nameMeslier
Squad number15Player nameDallas
Squad number10Player nameRaphinha
Squad number22Player nameHarrison
Squad number21Player nameStruijk
Squad number9Player nameBamford
Squad number43Player nameKlich
Squad number6Player nameCooper
Squad number19Player nameRodrigo
Squad number5Player nameKoch
Squad number3Player nameFirpo
Squad number11Player nameRoberts
Squad number17Player nameHélder Costa
Line-ups
Man Utd
Formation 4-2-3-1
1de Gea
29Wan-Bissaka2Lindelöf5Maguire23Shaw
39McTominay17Fred
21James18Bruno Fernandes6Pogba
11Greenwood
1de Gea29Wan-Bissaka2Lindelöf5Maguire23ShawBooked at 83mins39McTominaySubstituted forMaticat 69'minutes17Fred21JamesSubstituted forSanchoat 75'minutes18Bruno Fernandes6PogbaSubstituted forMartialat 75'minutes11GreenwoodSubstitutes
8Mata9Martial15Pereira20Dalot22Heaton25Sancho31Matic33Williams34van de BeekLeeds
Formation 4-4-1-1
1Meslier
2Ayling21Struijk6Cooper15Dallas
10Raphinha5Koch43Klich22Harrison
19Rodrigo
9Bamford
1Meslier2Ayling21Struijk6CooperBooked at 59mins15Dallas10RaphinhaBooked at 62mins5Koch43Klich22HarrisonSubstituted forHélder Costaat 69'minutes19RodrigoSubstituted forFirpoat 45'minutes9BamfordSubstituted forRobertsat 77'minutesSubstitutes
3Firpo4Forshaw11Roberts13Klaesson17Hélder Costa23Phillips38Summerville42Greenwood46ShackletonReferee:Paul TierneyAttendance:72,732Live Text
Match ends, Manchester United 5, Leeds United 1.
Second Half ends, Manchester United 5, Leeds United 1.
Foul by Hélder Costa (Leeds United).
Luke Shaw (Manchester United) wins a free kick on the left wing.
Foul by Mateusz Klich (Leeds United).
Victor Lindelöf (Manchester United) wins a free kick in the attacking half.
Attempt missed. Luke Ayling (Leeds United) right footed shot from the centre of the box misses to the left following a set piece situation.
Junior Firpo (Leeds United) wins a free kick in the attacking half.
Foul by Fred (Manchester United).
Attempt missed. Raphinha (Leeds United) left footed shot from the centre of the box is close, but misses to the right. Assisted by Tyler Roberts.
Luke Shaw (Manchester United) is shown the yellow card for a bad foul.
Raphinha (Leeds United) wins a free kick in the defensive half.
Foul by Luke Shaw (Manchester United).
Hélder Costa (Leeds United) wins a free kick in the defensive half.
Foul by Aaron Wan-Bissaka (Manchester United).
Attempt missed. Hélder Costa (Leeds United) right footed shot from outside the box is too high. Assisted by Liam Cooper with a headed pass following a set piece situation.
Hélder Costa (Leeds United) wins a free kick on the right wing.
Foul by Luke Shaw (Manchester United).
Attempt missed. Tyler Roberts (Leeds United) right footed shot from outside the box is close, but misses to the left.
Hand ball by Mason Greenwood (Manchester United).
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