Their manager, Alex Ferguson, had gambled on youth and triumphed against Port Vale in the previous round, but against the Premiership leaders the dice failed to roll for him. Even so, Newcastle required more than 80 minutes to break his team down.
A replay - just about the last thing either team wanted given their European commitments - was beckoning until Philippe Albert and Paul Kitson scored to give Newcastle a slightly flattering scoreline.
More worrying for United were the injuries they collected. Having fielded eight youngsters to spare the seniors, it was Denis Irwin (knee) and Lee Sharpe (ankle) who had to be taken off, and the latter will definitely be missing on Saturday when the teams meet at Old Trafford in the League.
'The younger players deserved the chance because of the way they played against Port Vale,' Ferguson said. 'We lived with them for more than an hour but Newcastle deserved to win because of the pressure they put on us towards the end. I wish them well, they've been a breath of fresh air in the Premiership this season.'
Fresh, when linked with faced, was the right word for the visitors.
Pallister, Irwin, Bruce and McClair were familiar; the rest of the starting line- up had the red supporters rapidly scanning their programmes before launching into 'There's only one . . .' There were seven changes from the side that defeated Blackburn on Sunday.
As expected, Newcastle began the stronger, but after Steve Howey had hit a Mancunian post with an 18th-minute volley it was the visitors' sharp interchanges of passing that became the dominant theme.
Keith Gillespie, a lamb in sheep's clothing given his Northern Ireland caps, twice nearly prised Newcastle apart, but his crosses were put narrowly wide by Nicky Butt and Steve Bruce. It was from the right wing, too, that the visitors' best chance of the night came, Bruce having a header cleared off the line by Marc Hottiger from David Beckham's 36th-minute corner.
In the second half experience told, however. Bruce had to clear after Andy Cole's shot had beaten Gary Walsh after 61 minutes and there were other efforts from Kitson and Steve Watson that went close.
Just as it appeared that the youngsters in red might hold out, Newcastle broke their resistance. Hottiger strode down the right and his cross was perfectly weighted for Albert. The Belgian entered the area at some speed and his header, from a range of about 10 yards, was so powerful that Walsh did not have an earthly of stopping it.
The Manchester United goalkeeper did not have much chance, either, with the second goal. Peter Beardsley, an otherwise quiet figure, played an immaculate pass between the centre-backs and Kitson finished with some accomplishment.
Newcastle United (4-4-2): Srnicek; Hottiger, Peacock, Howey, Beresford; Watson, Albert, Beardsley, Sellars; Kitson, Cole (Guppy, 63). Substitutes not used: Clark, Hooper (gk).
Manchester United (4-5-1): Walsh; Neville, Bruce, Pallister, Irwin (Sharpe, 50; Tomlinson, 72); Gillespie, Beckham, Butt, McClair, Davies; Scholes.
Substitute not used: Pilkington (gk).
Referee: T Holbrook (Walsall).Reuse content