The Premiership's leaders now visit its bottom club on 25 February for the dubious privilege of a trip to Newcastle. The replay is one of four matches United must play in 15 days before their European Cup quarter- final in Monaco.
Barnsley, who scored first through John Hendrie after a shocking error by Peter Schmeichel, were swiftly pegged back by Teddy Sheringham. But they left with mixed emotions: delighted to have drawn, but despairing of referee Mike Riley, who refused them a late penalty which even the United manager admitted was blatant.
Schmeichel's calamity came seven minutes before the end of an unexpectedly even first half. Twenty-four hours earlier, Mark Bosnich had thwarted Coventry with a piece of agility which recalled Rene Higuita's "scorpion" save. The miskick with which Denmark's finest gifted Barnsley the lead evoked another maverick moment by the Colombian keeper, which resulted in a Cameroonian goal.
Higuita memorably called it "a mistake as big as a house", by which criterion Schmeichel's gaffe was of stately-home proportions. Given a routine clearance by Gary Pallister's back-pass, he sliced the ball horribly across goal. Hendrie suppressed his surprise long enough to stroke it into the unguarded net.
Behind for the third consecutive home game, United drew level within four minutes with a goal fashioned and finished with a panache largely absent from their play. Ryan Giggs, handed a floating role, had already laid off one through-ball for Brian McClair to fire against an upright.
Now the Welshman killed another long pass on his chest before spotting Sheringham's run. Giggs' backheeled pass put the England striker clear in a central position, from which he passed the ball into the slender gap between David Watson and his left-hand post.
Barnsley, with the self-confessed Manchester City fan Ashley Ward frequently exposing Henning Berg's current frailty, lived dangerously when Jovo Bosancic underhit a pass to Watson. But the goalkeeper, determined to atone for October's aberration, managed the considerable feat of outsprinting Giggs to the ball.
The interval gave Ferguson a chance to rectify United's shortcomings, and David Beckham duly appeared. Barnsley's goal should have fallen within 50 seconds, Giggs sending a free header straight at Watson. However, the anticipated siege never quite materialised.
Barnsley continued to counter with menace and Martin Bullock, Oakwell's answer to Juninho, caused particular problems with his sinuous dribbling. One such run, 12 minutes from time, took him deep into the area, only for Hendrie to shoot wildly over.
The spot kick that never was came seven minutes from time when Gary Neville brought down Andy Liddell. By then, the poverty of United's imagination had been highlighted by the sight of Pallister marauding clumsily in the centre-forward position. As one press cynic put it: "Who needs Salas when you've got Pally?"
Goals: Hendrie (38) 0-1; Sheringham (42) 1-1.
Manchester United (4-4-2): Schmeichel; Clegg, Berg, Pallister, Irwin; P Neville, Johnsen (Beckham, h-t), McClair (G Neville, 79), Giggs; Sheringham, Nevland (Cruyff, 58). Substitutes not used: Casper, Van der Gouw (gk).
Barnsley (3-5-2): Watson; De Zeeuw (Appleby, 25), Moses, Morgan; Eaden, M Bullock, Bosancic, Redfearn, Krizan; Hendrie (Liddell, 81), Ward. Substitutes not used: Marcelle, Tinkler, Leese (gk).
Referee: M Riley (Leeds).
Bookings: Barnsley Ward, Bosancic.
Man of the match: Moses.Reuse content