Newcastle United claimed their second Old Trafford victory over Manchester United since 1972 to avenge their Carabao Cup final defeat at Wembley and pile the pressure on home manager Erik ten Hag.
First-half goals from substitute Miguel Almiron and Lewis Hall, his first for the club, were followed up by a solo effort from Joe Willock on the hour to give Newcastle their biggest away win over their hosts in 93 years as they cruised into the quarter-finals.
It was another desperate day for Manchester United and Ten Hag, who have lost eight of their opening 15 games for the first time since the 1962-63 season.
Coming just three days after they suffered another three-goal home humiliation at the hands of Manchester City, the home side’s weaknesses were again cruelly exposed.
Diogo Dalot was replaced at half-time following his failure to track Almiron’s right-wing burst for the opener.
Returning Brazilian midfielder Casemiro did not re-appear for the second-half either with Ten Hag evidently unimpressed by the former Real Madrid man.
Hall struck a fine second as he met Harry Maguire’s headed clearance with a first-time volley. Willock’s effort emulate Hall’s by finding the bottom corner after he had been allowed to run 30 yards unchecked before shooting after Sofyan Amrabat had lost possession on the halfway line.
In a week where the size of their kit has been questioned, Manchester United’s players could have done with shirts big enough to cover their heads as, for the second game running, they were booed off at the end of both halves.