Harry Maguire's late own goal came after he replaced Raphael Varane at half-timeManchester United conceded two own goals and lost Lisandro Martinez to a serious-looking injury in the final six minutes against Sevilla to put their Europa League hopes in jeopardy.
United looked to be coasting to a quarter-final first-leg victory at Old Trafford thanks to Marcel Sabitzer's first-half double.
However, after Antony had hit the crossbar, Sevilla came back into the contest and profited from a terrible ending to the game for Erik ten Hag's men.
First Tyrell Malacia diverted the ball past David de Gea after former Manchester City man Jesus Navas had pulled a low cross back from the goalline.
Then, two minutes into injury time, Youssef En-Nesyri's off-target header struck Harry Maguire to leave De Gea helpless as it flew into the net.
The scoreline is bad enough as it leaves United facing a battle to secure the semi-final spot they seemed to have virtually sealed.
However, the loss of Martinez is a major concern, particularly as Raphael Varane had to be replaced at half-time.
Martinez had to be carried from the field by his Argentina team-mates Gonzalo Montiel and Marcos Acuna and then left for the dressing room on a stretcher in obvious pain after catching his foot in the turf with no opponent near him.
Martinez injury fear
Lisando Martinez's Argentina team-mates Marcos Acuna and Gonzalo Montiel helped to carry him offHaving opted against replacing Marcus Rashford when his side were two goals up against Everton at the weekend and seeing the England man get injured, it was probably not a surprise when United boss Erik ten Hag took off key man Bruno Fernandes, plus Jadon Sancho and Anthony Martial after an hour.
At that point United had a healthy advantage, with Sabitzer profiting from excellent through balls from Fernandes and Martial and Ten Hag presumably reasoned it was a wise option not to take a risk with so many big games to come, knowing Fernandes is banned for the second leg anyway after he picked up another yellow card.
But the decision allowed Sevilla to gain some momentum. United's goal came under threat and eventually, their lead disappeared.
Arguably though, the extent of Martinez's injury is of more concern.
The Argentine has been a rock at the heart of United's defence this season and, given the clear pain he was in as he sat sadly by the touchline waiting to be carried to the dressing rooms, there must be huge uncertainty over when he will play again, which could place his side's season under a threat that previously did not seem to exist.
Martial's time to shine
If there is some comfort to be taken from a night that ended so badly, it came from the performance of Martial.
Ten Hag quoted "stats" in the build-up to the game when he said United were a better team with the Frenchman in it.
The problem is that, since he arrived from Monaco in 2015, United fans have seen the 27-year-old be maddeningly frustrating, capable of brilliance in one moment before disappearing for extended periods - either figuratively in terms of his contribution to the team or literally by being injured.
If ever there was a time for Martial to step up, this is it.
No timescale has been put on Rashford's absence but even if it was just to the end of the month - and the belief is it will be slightly longer - that would take in the rest of this tie, the FA Cup semi-final with Brighton and a crucial league game at Tottenham in the battle to secure a Champions League spot. Martial has to stay fit and he has to perform.
His contribution to Sabitzer's second goal emphasised why.
Collecting the ball inside the Sevilla half, Martial took his time, created some space, then delivered a perfect through ball. Immediately after he scored, Sabitzer pointed to Martial in grateful acknowledgement.
Martial's last involvement was to superbly hold-up possession as United cleared their lines from a Sevilla attack, setting in motion a move that ended with Antony firing against the crossbar.
Ten Hag has praised Wout Weghorst for his contribution but the on-loan Burnley forward is not in the same class.
Player of the match
NavasJesús Navas
Sevilla
Squad number16Player nameNavas
Squad number15Player nameEn-Nesyri
Squad number24Player namePapu Gómez
Squad number7Player nameSuso
Squad number10Player nameRakitic
Squad number55Player nameOcampos
Squad number20Player nameFernando
Squad number21Player nameTorres
Squad number19Player nameAcuña
Squad number6Player nameGudelj
Squad number17Player nameLamela
Squad number23Player nameMarcão
Squad number13Player nameBono
Squad number14Player nameNianzou
Squad number2Player nameMontiel
Line-ups
Man Utd
Formation 4-2-3-1
1de Gea
29Wan-Bissaka19Varane6Li Martínez12Malacia
18Casemiro8Bruno Fernandes
21Antony15Sabitzer25Sancho
9Martial
1de Gea29Wan-Bissaka19VaraneSubstituted forMaguireat 45'minutes6Li MartínezSubstituted forat 86'minutes12Malacia18Casemiro8Bruno FernandesBooked at 41minsSubstituted forEriksenat 62'minutes21AntonyBooked at 65minsSubstituted forPellistriat 81'minutesBooked at 89mins15Sabitzer25SanchoSubstituted forElangaat 63'minutes9MartialSubstituted forWeghorstat 62'minutesSubstitutes
2Lindelöf5Maguire14Eriksen17Fred20Dalot27Weghorst28Pellistri31Butland36Elanga50Vítek55IqbalSevilla
Formation 4-2-3-1
13Bono
2Montiel14Nianzou23do Nascimento Teixeira19Acuña
20Reges6Gudelj
55Ocampos10Rakitic21Torres
17Lamela
13Bono2MontielBooked at 11minsSubstituted forGómezat 90'minutes14NianzouSubstituted forFernández Sáenz de la Torreat 73'minutes23do Nascimento Teixeira19AcuñaBooked at 72mins20Reges6GudeljBooked at 58mins55Ocampos10RakiticBooked at 25mins21TorresSubstituted forNavasat 45'minutes17LamelaBooked at 38minsSubstituted forEn-Nesyriat 67'minutesSubstitutes
1Dmitrovic3Alex Telles4Rekik7Fernández Sáenz de la Torre12Mir15En-Nesyri16Navas24Gómez25Gil31Flores44BadéLive Text
Match ends, Manchester United 2, Sevilla 2.
Second Half ends, Manchester United 2, Sevilla 2.
Attempt missed. Marcão (Sevilla) header from the centre of the box misses to the right. Assisted by Ivan Rakitic with a cross following a corner.
Corner, Sevilla. Conceded by Aaron Wan-Bissaka.
Wout Weghorst (Manchester United) wins a free kick in the defensive half.
Foul by Nemanja Gudelj (Sevilla).
Delay over. They are ready to continue.
Delay in match (Manchester United).
Own Goal by Harry Maguire, Manchester United. Manchester United 2, Sevilla 2.
Attempt missed. Youssef En-Nesyri (Sevilla) header from the centre of the box misses to the right. Assisted by Lucas Ocampos with a cross following a corner.
Corner, Sevilla. Conceded by Anthony Elanga.
Corner, Sevilla. Conceded by David de Gea.
Attempt saved. Youssef En-Nesyri (Sevilla) header from the centre of the box is saved in the bottom left corner. Assisted by Marcos Acuña with a cross.
Attempt blocked. Nemanja Gudelj (Sevilla) right footed shot from outside the box is blocked.
Substitution, Sevilla. Papu Gómez replaces Gonzalo Montiel.
Facundo Pellistri (Manchester United) is shown the yellow card for a bad foul.
Foul by Facundo Pellistri (Manchester United).
Marcos Acuña (Sevilla) wins a free kick in the attacking half.
Attempt saved. Suso (Sevilla) left footed shot from outside the box is saved in the top centre of the goal. Assisted by Gonzalo Montiel.
Lisandro Martínez went off injured after Manchester United had used all subs.
