Michael Boulding's opportunist goal in first half stoppage time at Plainmoor settled it, condemning Torquay to their third successive defeat.
Boulding had his first shot blocked from strike partner Michael Chopra's breakaway run and cross, but he made no mistake from the rebound.
Torquay, without suspended skipper Craig Taylor, did not force a serious save from Barnsley keeper Ross Turnbull in the whole match.
And, without a series of spectacular saves by Icelandic goalkeeper Olafur Gottskalksson, Barnsley would have won much more easily.
Torquay went into the match buoyed by the club record £75,000 signing of striker Leon Constantine from Peterborough. But Constantine was one of many players who were virtually anonymous.
Just after half-time Lee Canoville cleared a Boulding side-foot off the Torquay line.
It took Torquay 66 minutes to force their one and only corner.
Torquay made little impression on Barnsley's outstanding centre-backs Tony Vaughan and Anthony Kay.
Barnsley manager Paul Hart did not see the need to make any substitutions in the match, while Torquay boss Leroy Rosenior had made all his three changes within an hour.
Barnsley always looked the more solid, confident side, with left-back Tom Williams always prepared to get forward on raids and he forced Gottskalksson into making two fine saves.
Torquay needed to hit back early in the second half to lift their subdued supporters, but instead it was Barnsley who dominated to the finish.
Boulding should have made it 2-0 when Chopra laid on a great chance 20 minutes from time. And both Boulding and Chopra went close to completing Torquay's misery in the closing stages.
After a run of only one defeat in eight games, Torquay have now run into a brick wall and have slid back into trouble.
That's in contrast to Barnsley - after only one win in eight games, they have now won three on the trot and without conceding a goal.