Coming into the contest on the back of a humiliating defeat at Sevilla in midweek, United boss Erik ten Hag demanded a positive response from his under-fire players.
However, any hopes that a trip to Wembley might provide the perfect platform for the Red Devils to bounce back were quickly dampened as Roberto De Zerbi’s well-drilled Brighton side dominated the opening half-hour.
David de Gea had to be on his toes to keep out an early free-kick from Alexis Mac Allister, before Julio Enciso and Kaoru Mitoma each missed the target with good opportunities inside the box.
Having tasted defeat just once in their last nine matches across all competitions, the confident Seagulls continued to probe for an opener with the interval looming. However, for all Brighton’s possession, it was United who came closest to breaking the deadlock with Bruno Fernandes firing a low strike narrowly wide of the far post.
Having shown small signs of improvement towards the end of the first half, the Red Devils emerged after the restart desperate to stamp their authority on proceedings.
It was Brighton though who looked the more dangerous of the two sides in the final third as Enciso saw a stinging drive superbly thwarted by De Gea, and Danny Welbeck directed a close-range header wastefully over the bar.
With the match tantalisingly poised going into the final 20 minutes, both sides went in pursuit of a decisive winning goal, however, clear-cut chances came at a premium with neither defence wilting under pressure.
This continued through the final stages as the contest progressed into extra-time, where Robert Sanchez came to Brighton’s rescue, diving brilliantly to thwart a deflected strike from Marcus Rashford.
Ultimately, this was as close as either side came to finding a breakthrough during a frantic finale as Mitoma saw another half-chance go begging, leaving the absorbing tie to be settled by the lottery of a penalty shoot-out.
In a battle of nerve, both sides were faultless from their first six spot-kicks, and after Solly March blasted Brighton’s seventh penalty over the bar, Victor Lindelöf held his nerve to send United in a 21st FA Cup final, inflicting a third successive shoot-out defeat on the Seagulls.
Flashscore Man of the Match: David de Gea (Manchester United)
