Manchester United suffered a humiliating Carabao Cup exit at Old Trafford as Brighton came from two goals down to reach the last 16.

United head coach Michael Carrick had to bring on skipper Bruno Fernandes 18 minutes from time in a desperate attempt to salvage the game after watching his side concede twice in four second-half minutes.

It was the first time United had led at home by two goals and lost since they were beaten 3-2 by Tottenham in 1976, half a century ago.

The small band of Brighton fans were jubilant as they celebrated in the corner of Old Trafford, with the home fans booing their team off at the final whistle.

It was the worst possible outcome for United and Carrick, still reeling from the stunning Manchester derby defeat by 10-man City - followed by 15-year-old academy star JJ Gabriel informing the club of his intention to quit.

United thought they had the perfect response when their other highly rated youngster Shea Lacey marked his first senior start with a well-taken goal after just eight minutes.

Mason Mount doubled their advantage two minutes later when he drove home the rebound from a Marcus Rashford effort that had been blocked.

At that point, it looked like being a good night for Carrick and his team.

But Charalampos Kostoulas pulled one back just before half-time. Brighton skipper Pascal Gross levelled when he was left on his own on the edge of the area and had time to turn on to a clearance from halfway and send his shot beyond Wales goalkeeper Karl Darlow, who was making his United debut.

Four minutes later, Kostoulas turned supplier as he cut the ball back for substitute Maxim de Cuyper to finish.

Jason Steele denied Marcus Rashford an equaliser at one end, but United were reliant on Darlow denying Diego Gomez a fourth Brighton goal.

After their humbling EFL Cup loss at League Two Grimsby last season, followed by Brighton's FA Cup triumph here in January, it was a third successive domestic cup loss for Manchester United.