Gary McSheffrey struck after nine minutes but the Sky Blues did not put the game to bed until five minutes from the end when substitutes Carl Baker and Jordan Clarke scored their first senior goals.
Barnsley remain without an away league win in 14 matches. History suggested the Ricoh Arena would not be the place they would end that run with the Tykes failing to win at Coventry in 21 visits since August 1923.
And Mark Robins' side did not make a good start. Lukas Jutkiewicz threatened early on before his strike partner McSheffrey found the net.
Coventry-born McSheffrey struck his second goal of the season, latching on to Clive Platt's header before beating former Sky Blues keeper Luke Steele from the left side of the area.
However, Coventry did not have it all their own way and Jacob Butterfield and Goran Lovre forced Keiren Westwood into fine saves with shots from the left-hand side of the box.
At the other end, a superb 20-yard effort from Aron Gunnarsson narrowly cleared the crossbar and Steele had to push away a McSheffrey strike.
Butterfield flashed a shot wide straight after the restart and Westwood was called upon to make a parrying save to keep out Adam Hammill's shot from the edge of the area.
Gunnarsson headed wide midway through the second half and Stephen Foster did likewise for Barnsley with 10 minutes remaining as the Tykes' final chance to get back into the game went begging.
Baker netted following a solo run in the 86th minute, finally beating Steele with a low shot from 18 yards out.
Clarke then spotted Steele off his line in the final minute and his shot from the right side of the box nestled in the bottom corner.