A 95th-minute penalty from Brian Howard saw Barnsley come from two goals down to earn a dramatic point at Scunthorpe.
Scunthorpe took a two-goal lead courtesy of goals from Ian Morris and Kelly Youga.
But Grant McCann's 74th minute goal gave the Tykes some hope in a game that looked to be slipping away.
And with just seconds of injury-time remaining, referee Clive Oliver penalised Andy Crosby for handball and Howard duly dispatched the equaliser.
Scunthorpe boss Nigel Adkins:
"It's the fourth game in 10 days but to play the way we did in the first half was commendable.
"We tried to keep them out then in injury-time a refereeing decision again has given them a penalty.
"Yes the ball has hit Andy Crosby's hand, yes he doesn't know anything about it."
Barnsley boss Simon Davey:
"I thought we were diabolical in the first half.
"At half-time we needed to make sure we got a reaction from the players and we did. I thought based on the second half it was a thoroughly deserved point.
"The second-half performance will serve as a nice platform for us. It's nice to take the confidence with us into the FA Cup this weekend."
Scunthorpe: Murphy, Youga, Crosby, Baraclough, Williams, Hayes (Taylor 77), Goodwin, Morris, Cork, Hurst (Forte 77), Paterson (Ameobi 82).
Subs Not Used: Lillis, Seck.
Booked: Goodwin, Hayes, Baraclough.
Goals: Morris 45, Youga 47.
Barnsley: Muller, Foster, Souza, Nyatanga (Mostto 84), Van Homoet, Campbell-Ryce, Togwell, Howard, Devaney (McCann 46), Odejayi, Ferenczi (Coulson 46).
Subs Not Used: Ricketts, Hassell.
Booked: Devaney.
Goals: McCann 74, Howard 90 pen.
Att: 6,897
Ref: Clive Oliver (Northumberland).
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