Sir Alex Ferguson made 11 changes from United's defeat by Liverpool on Sunday and they went ahead when Anderson's corner was headed in by Danny Welbeck. Barnsley went close when Daniel Bogdanovic hit the post, but Michael Owen's expert finish doubled the lead.Gary Neville was shown a straight red card for a challenge on Adam Hammill, but Barnsley could find no way through.
They had enough chances to get back on level terms, but some profligate finishing cost them any chance of a famous upset at Oakwell.
It was the perfect opportunity for Ferguson to give some of his senior players who have not been playing regularly in the first team some much-needed competitive football. Neville and Wes Brown came into the defence, Anderson was brought into the midfield and Owen started only his fifth game for the club, while Gabriel Obertan made his first start since a £3m summer move from Bordeaux.
Ferguson's side showed Barnsley no mercy in a dominant opening spell as Welbeck thumped home a header with only six minutes on the clock. It could quickly have got worse as both Welbeck and Obertan forced fine saves from Luke Steele, the first chance coming after an outrageous 60-yard pass from the influential Anderson.
Barnsley were perhaps guilty of giving United too much respect, but they soon improved and Bogdanovic nodded against a post before Stephen Foster twice headed off target from good positions as United consistently failed to deal with corners.
The hosts were beginning to look like the better side, but they had not accounted for the predatory finishing instincts of master goal-scorer Owen. Having sliced one effort wide early in the second half, he made the Tykes pay with a stunning solo goal on the hour mark. Owen rolled back the years as he picked the ball up outside the Barnsley area, slipped it through a defender's legs and surprised Steele by taking his shot early, clinically rolling it into the far corner from 16 yards. (BBC Sport)