Manchester United tumbled out of the Premier League's top four as Jay Rodriguez's first goal in 50 league games earned bottom club Burnley a precious point at Turf Moor.
For the second game running, United dominated the play and had most of the chances, with Paul Pogba putting them ahead with his first goal of the season.
But just as against Middlesbrough in the FA Cup, the visitors were made to pay for their profligacy.
On this occasion, they had two first-half goals disallowed, while Nick Pope made excellent saves to deny Marcus Rashford, Edinson Cavani and Raphael Varane.
In contrast, Burnley made the most of their brief spell in the ascendency at the start of the second period, as Rodriguez ran onto Wout Weghorst's through-ball to score his 100th career league goal.
It means United drop to fifth, with the three teams below them all capable of catching them if they win their games in hand.
Burnley are four points from safety, but are three unbeaten, even if their run without a win now extends to 10 matches.
Pogba's sublime finish from Luke Shaw's cut-back in the 18th minute was a thing of beauty.
Given far too much space inside the Burnley penalty area, Pogba astutely steered his first-time shot into the roof of the net, giving goalkeeper Pope no chance.
It was one of those moments which underline Pogba's status as one of the best midfielders in the world.
But there is another side to the £90m man. Taking possession inside his own half close to the touchline, he spun round, away from a Burnley defender into space and was perfectly placed to switch play across the pitch.
Instead, Pogba smashed the ball down the touchline to no-one. Those infuriating moments have happened far too frequently since he returned to Old Trafford for a second time in 2016 and explains why not many United fans will shed a tear if Pogba leaves the club for nothing for a second time when his contract expires at the end of the season.
When United were chasing the game, Pogba didn't really step up either, although for the second successive game, interim boss Ralf Rangnick will wonder about a VAR decision that went against his team.
This time, it was Varane who had what would have been his first goal for the club ruled out.
Even though the Frenchman was clearly onside as he ran onto a Bruno Fernandes free-kick before steering a header into the far corner, Harry Maguire was offside before he blocked Rodriguez's attempt to get back ad defend. After consulting the monitor, referee Mike Dean ruled the effort out.
Another goal, when Josh Brownhill turned in a Rashford cross, was disallowed by a foul from Pogba on Ben Mee in the build-up.Follow live text and radio commentary of Burnley v Manchester United, plus Tuesday's two other Premier League matchesGo straight to all the best Burnley contentVisit our Man Utd page
New boy Weghorst shows his strengths
Burnley boss Sean Dyche invested £12m in Netherlands striker Weghorst last month as a replacement for Chris Wood, who left for relegation rivals Newcastle.
Against Watford on Saturday and the first-half here, Weghorst was on the periphery, with a few decent touches but not much else to show for his efforts.
Within the first 10 minutes of the second period, though, the 29-year-old showed what an asset he could be.
Questions could be asked about Maguire letting Weghorst turn and run free in the build-up to Rodriguez's equaliser but the forward had the nimbleness to take advantage and his pass was perfect.
Weghorst then brought an excellent full-length save out of De Gea with a shot from outside the box.
It was an object lesson in maximising what you have.
And while Newcastle's win took the gloss off Burnley's result, Dyche's side have now avoided defeat against Arsenal and Manchester United in the past three games and provides some reason for optimism ahead of Liverpool's visit to Turf Moor on Sunday.
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Squad number1Player namePope
Squad number14Player nameRoberts
Squad number5Player nameTarkowski
Squad number6Player nameMee
Squad number23Player namePieters
Squad number11Player nameMcNeil
Squad number18Player nameWestwood
Squad number8Player nameBrownhill
Squad number20Player nameCornet
Squad number19Player nameRodriguez
Squad number9Player nameWeghorst
Squad number10Player nameBarnes
Squad number17Player nameLennon
Squad number1Player namede Gea
Squad number20Player nameDiogo Dalot
Squad number19Player nameVarane
Squad number5Player nameMaguire
Squad number23Player nameShaw
Squad number6Player namePogba
Squad number39Player nameMcTominay
Squad number10Player nameRashford
Squad number18Player nameBruno Fernandes
Squad number25Player nameSancho
Squad number21Player nameCavani
Squad number7Player nameCristiano Ronaldo
Squad number14Player nameLingard
Squad number36Player nameElanga
Formation 4-4-21Pope14Roberts5Tarkowski6Mee23PietersBooked at 74mins11McNeil18Westwood8BrownhillBooked at 77mins20CornetSubstituted forLennonat 69'minutes19RodriguezSubstituted forBarnesat 88'minutes9Weghorst
Formation 4-2-3-11de Gea20Dalot19Varane5MaguireBooked at 62mins23Shaw6Pogba39McTominaySubstituted forLingardat 80'minutes10RashfordSubstituted forElangaat 85'minutes18Bruno Fernandes25Sancho21CavaniSubstituted forCristiano Ronaldoat 68'minutes
Match ends, Burnley 1, Manchester United 1.
Second Half ends, Burnley 1, Manchester United 1.
Attempt missed. Harry Maguire (Manchester United) with an attempt from the centre of the box is close, but misses to the left. Assisted by Bruno Fernandes with a cross following a corner.
Corner, Manchester United. Conceded by Ashley Westwood.
Attempt blocked. Jesse Lingard (Manchester United) right footed shot from outside the box is blocked. Assisted by Jadon Sancho.
Attempt blocked. Cristiano Ronaldo (Manchester United) left footed shot from the left side of the box is blocked. Assisted by Luke Shaw.
Attempt blocked. Bruno Fernandes (Manchester United) right footed shot from outside the box is blocked. Assisted by Paul Pogba.
Corner, Manchester United. Conceded by Nick Pope.
Attempt missed. Cristiano Ronaldo (Manchester United) header from the centre of the box is high and wide to the right. Assisted by Anthony Elanga with a cross.
Substitution, Burnley. Ashley Barnes replaces Jay Rodriguez.
Substitution, Manchester United. Anthony Elanga replaces Marcus Rashford.
Attempt missed. Wout Weghorst (Burnley) left footed shot from the centre of the box misses to the right. Assisted by Dwight McNeil with a cross.
Substitution, Manchester United. Jesse Lingard replaces Scott McTominay.
Attempt missed. Cristiano Ronaldo (Manchester United) header from the centre of the box is too high. Assisted by Luke Shaw with a cross following a corner.
Corner, Manchester United. Conceded by Ben Mee.
Attempt blocked. Raphaël Varane (Manchester United) left footed shot from the left side of the six yard box is blocked. Assisted by Marcus Rashford.
Corner, Manchester United. Conceded by Ashley Westwood.
Josh Brownhill (Burnley) is shown the yellow card for a bad foul.
Paul Pogba (Manchester United) wins a free kick in the attacking half.
Foul by Josh Brownhill (Burnley).
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