Even Barnsley's match-winner Clint Marcelle was sorry to have turned the dream debut of City's 17-year-old Geff Whitley into a nightmare.
Caretaker boss Asa Hartford had drafted Whitley in because of injuries and given him the task of man-marking the slippery Marcelle, a former Oporto player.
Up until injury time, Zambia-born Whitley had had a splendid game, even though Marcelle, a Trinidad World Cup international, slipped from his grasp in the 67th minutes to put Barnsley ahead.
Then with only a minute of extra time left, the youngster attempted an ill-judged back pass to keeper Andy Dibble that fell short.
In a flash the fleet-footed Marcelle pounced and neatly rounded Dibble to slot home a dramatic winner that keeps Barnsley top of the first division with a 100 per cent record.
Whitley held his head in agony, and Marcelle said afterwards: "I felt so sorry for Whitley.
"He is such a talented young player and clearly has a great future in the game but that's the way it goes."
That makes it four goals in five matches for the impressive Marcelle.
His winner left City's 26,000 crowd stunned. They must have felt that when Nigel Clough cracked home a crisp equaliser in the 74th minute, they might after all notch up their third successive home win.
Uwe Rosler twice came desperately close to scoring and City - with midfield wizard Georgi Kinkladze in fine form - had far more drive about them than in their extraordinary lucky victory over Charlton in mid-week.
Hartford's five-game reign has now seen City win two and lose three.
He said: "I thought we were worth a draw and played a lot better than we did in midweek when we won.
"We must get some fresh players in, because of all the injuries to the first-team squad men. It was cruel luck for Geff right at the end. He had done such an impressive job until that late slip.
"But everybody at the club still has no doubt that he will be a great player in the future."
Barnsley have now scored ten goals in four straight wins, a marvellous start that helps to explain why their manager Danny Wilson keeps being tipped for the City hot-seat.
But Wilson, once on City's books as a player, said: "I'm happy at Barnsley and we have the strongest squad we've had for a long time.
"People will say we are going to get carried away by this start, but we will keep our feet firmly on the ground.
"City have a tremendously talented squad and some magnificent supporters and once they get a top manager in they'll go from strength to strength."