There are differing definitions of a trophy drought at these two clubs. It felt like a long time ago that Manchester United were winning this competition and the Europa League under José Mourinho. It was 2017 and the barren years since then had added up to their longest sequence without silverware since the early 1980s.

Newcastle, of course, could see that and reraise it to 54 years – the chasm to their famous Fairs Cup triumph. This final, Newcastle’s first since the FA Cup of 1999 when they took on the same opponents, was all about who could chart fresh territory, who could own the occasion. As in 1999, it was the Reds – and by the same scoreline.

Related: Newcastle not yet an evil-empire side but cup final feels like a springboard | Jonathan Liew

Erik ten Hag was the picture of elation when it was all over, dancing a South American jig with Lisandro Martínez and Antony, his Old Trafford revolution given the hard edge that he had demanded. And, really, it was all pretty comfortable after a two-goal salvo towards the end of the first half.

The excellent Casemiro got the first with a towering header, Marcus Rashford forced the second with a shot that deflected off Sven Botman to wrongfoot the unfortunate Loris Karius and United were happy for the second half to become a nonevent, a gradual countdown to glory.

Ten Hag’s team have lost only once in 21 matches, they are alive and kicking in the last 16 of both the FA Cup and Europa League and they are sitting pretty in third in the Premier League. It is looking and feeling extremely sweet. And if Avram Glazer, who was picked out by the cameras here, and his family could now leave as the United fans demanded throughout …

Newcastle have been transformed since the Saudi Arabia-led takeover of October 2021, Eddie Howe benefiting from a £240m spend on new players and shaping a team of steel and spirit, one that has proved extremely difficult to break down. But the cold truth was that after a decent start, they went with a whimper.

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It had been quite the scene 15 minutes or so before kick-off, the Newcastle end packed, the black and white flags waving. The other half of the stadium took its time to fill up, the red and whites seemingly more relaxed and au fait with it all. There was no coordinated pre-match display from them. But it was their fans who could stick around for what mattered – the trophy presentation.

The mood would shift sharply within the Newcastle support after the goals. Before the Casemiro breakthrough, they had dared to dream, with Allan Saint-Maximin almost drawing first blood on 32 minutes. He had already drawn Diogo Dalot into a yellow-card tackle. Now he tricked past the full-back, who was substituted at half-time, cut inside and unloaded from a tight angle. David de Gea had his angles right and he blocked.

It was Manchester United who did unlock the game and it was galling from a Newcastle point of view that Casemiro’s fifth goal of an already stellar season came from a set piece. It was a whipped Luke Shaw free-kick from the left after Rashford had been barged over by Bruno Guimarães – Newcastle did not like the decision – and Casemiro achieved the not insignificant feat of getting between Fabian Schär and Botman to power home.

Newcastle’s heads spun and their opponents completed the devastating one-two punch with the help of an iffy moment from Karius. The third-choice goalkeeper’s story had been well told in the buildup and many wanted him to excel; to recover from the concussion-induced nightmare on his last appearance for an English club – Liverpool’s Champions League final loss to Real Madrid in 2018.

But when Rashford, passed fit after an injury scare, surged on to a Wout Weghorst pass up the inside left, took a touch and saw a mis-hit shot deflect off Botman, Karius could not react in time. The ball looped up and over his overstretched hands.

Related: Ten Hag delighted at ending Manchester United trophy drought

Dan Burn might have pulled one back in first-half stoppage time, heading wide after Kieran Trippier had worked a short corner. The fine margins were against Newcastle and they struggled to keep their composure. Joelinton, for example, swiped at Antony and dragged down Casemiro after seeing the former take the mickey out of Burn. He was booked.

Howe went for broke at the start of the second half, introducing Alexander Isak up front alongside Callum Wilson. Newcastle needed something. Saint-Maximin continued to look like their best creative bet and that said a lot given the erratic nature of his end product.

Saint-Maximin called for more noise from the black-and-white hordes after winning a corner; whipping them up, partly out of frustration. Joelinton would later do the same thing after seeing a shot blocked.

And yet from that corner won by Saint-Maximin, Trippier ended up going back to Burn, who was almost on the halfway line. Burn then hit a raking diagonal back to Trippier, who lost possession, and the club’s fans scratched their heads.

The Newcastle substitute Jacob Murphy fizzed a low shot wide on 88 minutes while Joelinton worked De Gea with a header in stoppage time but it was too little, too late. It was United who were the likelier scorers of the next goal, more dangerous on the break, and they would have got it had Karius not denied Rashford or Bruno Fernandes passed to the substitute Jadon Sancho rather than shooting. Karius made a smart save.