There were big chances for both sides in a goalless 120 minutes at Wembley, with Bruno Fernandes dragging a first-half effort wide while Danny Welbeck and Julio Enciso were among those to go close for the impressive Seagulls.
With every heavy touch and missed opportunity, penalties appeared increasingly inevitable and so it proved, as the semi-final went to the spot. Player after player stepped up and held their nerve, 12 perfect penalties extending the shootout, but Solly March blazed his effort over the bar and that set the stage for Lindelof step up as United’s hero.
He fired his penalty into the top corner to start the celebrations in the red camp, with a Manchester derby now to come on June 3, the first time the two sides have met in an FA Cup final.
Manchester City beat Sheffield United on Saturday to book their return to Wembley, and it could well be down to United to halt their rivals’ treble bid at the end of the season.
Luke Shaw, Anthony Martial and Marcus Rashford were all fit to start for United in a big boost as they looked to respond to the midweek disappointment of being knocked out of the Europa League, while Danny Welbeck led the line for Brighton against his former club.
The Seagulls made the better start at Wembley and could have taken an early lead, as Alexis Mac Allister’s free-kick was well-saved by David de Gea before Enciso fired just wide from the edge of the box.
Fernandes was United’s main threat, when not engaging in an amateur dramatics performance. Three times he went down in the first-half before making a swift and miraculous recovery, but the biggest moment came as he dragged wide of the far post when played clean through on goal.
It was all Brighton immediately after the break, though again they could not make the most of it. Enciso hammered an effort at goal and was denied by a superb save from De Gea, before Welbeck headed over a massive chance from the resulting corner when free at the back post just a few yards out.
United again responded, Antony having a couple of tame efforts saved and Fernandes firing a free-kick from just outside the area straight into the wall, but it became increasingly tense as the clocked ticked towards 90 minutes and it remained goalless in normal time.
Chances were at a premium in extra-time, with the best two both falling for United. First two substitutes combined, as Jadon Sancho clipped a cross into the middle where Marcel Sabitzer won the header but glanced it wide, before Robert Sanchez at full stretch produced a stunning save to turn Rashford’s deflected effort behind.
Brighton had their moment to win it with a few minutes remaining, as Kaoru Mitoma and Mac Allister combined with a brilliant one-two, but the Seagulls winger took a heavy touch just as he looked set to score from six-yards out. Penalties it was.
It was a masterclass from 12 yards for much of the shootout, with the pressure on Sabitzer to take it to the sudden death and he just about did so, despite Sanchez getting a big hand to his spot-kick.
The back of the net continued to be found, but March was unable to hit the target as he sent his spot-kick into the stands and Lindelof did the rest to ensure United will be back at Wembley in early June.