Danny Welbeck piled more misery on former club Manchester United, as his 64th-minute stunner helped Brighton to a 2-1 win over the Red Devils in the FA Cup. 

Brighton were forced to navigate a nervy ending at Old Trafford after Benjamin Sesko halved the deficit late on, but the visitors held on to progress after Shea Lacey was sent off. 

Both sides made a lightning start to the encounter, with Jason Steele rushing out of his goal to deny Diogo Dalot's attempt inside the opening two minutes. 

Dalot then blazed high over the crossbar, before Bruno Fernandes forced another smart stop from Steele soon after following a quick free-kick routine with Kobbie Mainoo. 

But for all of their pressure, United fell behind when Brajan Gruda thumped the ball home in the 12th minute, after Georginio Rutter saw his initial header cleared off the line. 

Senne Lammens then almost gifted Brighton a second two minutes later after his pass was cut out by Welbeck, but the Belgian recovered well to deny the Brighton forward. 

United continued to turn the screw before the break as Lisandro Martinez, Fernandes and Matheus Cunha came close, but Brighton doubled their lead just after the hour. 

Joel Veltman's pass down the left was gathered by Gruda, who laid the ball off to Welbeck, with the latter taking a touch before rifling a fierce left-footed drive into the roof of Lammens' net. 

United got one back five minutes from time when Sesko nodded Fernandes' corner home, but their hopes of a comeback were dashed when Lacey picked up two yellow cards in the space of two minutes. 

Data Debrief: Wonderful Welbeck ensures United go trophyless

Welbeck left United in 2014 for Arsenal and has made a thing of scoring against his former club. His goal here was his eighth against the Red Devils in all competitions, his joint-most against an opponent in his club career (also eight against West Ham). 

His strike also ensured another trophyless season at Old Trafford. Indeed, United have now been eliminated from both the FA Cup and EFL Cup in their opening tie in the same season for the first time since 1981-82.

For interim boss Darren Fletcher, he will be left to rue a glut of missed chances for his team. United ended the contest with an expected goals (xG) total of 1.73 from their 18 shots, compared to Brighton's 1.13 from their 13 attempts. 

But United's misery was compounded by the late dismissal of Lacey who, at 18 years and 227 days old, became the first teenager to be sent off for the Red Devils in all competitions since Luke Shaw against West Ham in February 2015.