It was the nerveless Alexis Mac Allister who blasted home the decisive spot kick deep in injury time to claim a memorable win and keep their European hopes on track.
Albion were out to avenge their FA Cup semi-final loss to the Red Devils at Wembley Stadium just two weeks ago.
The game remained goalless following a lively opening 45 minutes in which Antony fired wastefully wide after Bruno Fernandes’ pass carved open Albion’s defence inside two minutes, before Kaoru Mitoma intercepted an under-hit Victor Lindelof pass and raced clear at the other end only to thump his effort into the head of David De Gea with Julio Enciso awaiting a tap-in.
United goalkeeper De Gea was visibly shaken by the unconventional stop but was deemed fit to continue after receiving treatment.
Casemiro later headed narrowly over for Ten Hag’s side, while Brighton keeper Jason Steele produced smart saves to deny low efforts from Marcus Rashford and Martial.
After the break Brighton had their chances, most notably when Danny Welbeck sidefooted over from Mitoma’s pass, and Steele once again produced a fine stop to thwart Fernandes.
Mitoma also felt aggrieved when he was bundled over in the box by Wan-Bissaka, referee Andre Marriner waved it away and there was no further action following a brief VAR check. Chants of ‘the Premier League is corrupt’ bellowed around the stadium.
Solly March, the man who missed the penalty in the semi-final shootout, was excellent from the bench and fired a couple of efforts close, while Mac Allister forced a late low save from De Gea down sharply to his right.
Albion pushed to the end and snatched the lead deep into added time when Mac Allister converted from the penalty spot after Luke Shaw was penalised for handball following VAR intervention.
Another cracking and high quality match...Here’s how the Albion players rated...
![Brighton's Argentinian midfielder Alexis Mac Allister (C) celebrates with teammates on the pitch after his late winner against Manchester United](https://www.sussexexpress.co.uk/webimg/b25lY21zOmEyODZhOTA5LWNmZjQtNDkxOC1iNWE1LWViMGNmNjc2M2Q5MjoxNzNjZTE1MC1iM2EwLTQzYzctYWJkYi1kMGQ2MTQ2MDljZjI=.jpg?crop=3:2&width=594)
1.
Brighton's Argentinian midfielder Alexis Mac Allister (C) celebrates with teammates on the pitch after his late winner against Manchester United Photo: GLYN KIRK
![Two nice saves at his near post to deny Rashford in the first half. A vital save from Fernandes in the second half from rare attack. Distribution was sound as well. Hard to see Sanchez getting back in at the moment. Great display](https://www.sussexexpress.co.uk/webimg/b25lY21zOjExMzZlNGEyLTdlMzItNGVlOC04ZDEyLTRlMjdiYWY1NmY2Mjo4YzE0M2M1Yy0yZTRlLTRmNmQtODQ1NC1iMjdkOWIzMWRiZTE=.jpg?crop=3:2&width=594)
2. Jason Steele 8
Two nice saves at his near post to deny Rashford in the first half. A vital save from Fernandes in the second half from rare attack. Distribution was sound as well. Hard to see Sanchez getting back in at the moment. Great display Photo: Gareth Copley
![Played at right back and linked well with Buonanotte. Crunching in the tackle and bombed forward at every opportunity. Brilliant display in an unfamiliar position. I hope Brighton can keep him.](https://www.sussexexpress.co.uk/webimg/b25lY21zOmU5NGNlMGEwLTI5MjgtNDY1OS04YmI1LTNhNTVlOGViZWRmMTphYWNjNTJjMS05MGY2LTQzNDYtYjBlMC0yZGYxMzRlZGE0ZWY=.jpg?crop=3:2&width=594)
3. Moises Caicedo 9
Played at right back and linked well with Buonanotte. Crunching in the tackle and bombed forward at every opportunity. Brilliant display in an unfamiliar position. I hope Brighton can keep him. Photo: GLYN KIRK
![Looks back to his very best. Unlucky with a header on 16 minutes from a corner. Sound on the ball.](https://www.sussexexpress.co.uk/webimg/b25lY21zOmY2NWM0ZGUyLTY1NTEtNDQ5MC04OGNkLTE0Zjg4YWFkYTFhZToxMWMxZmM5MC00ZjJjLTRlMTktYjJiNi1hNDZkMDBjNzk1MTk=.jpg?crop=3:2&width=594)
4. Adam Webster 8
Looks back to his very best. Unlucky with a header on 16 minutes from a corner. Sound on the ball. Photo: Ryan Pierse