An early goal by skipper Conor Hourihane earned Barnsley their fourth straight away win as they survived strong pressure from hosts Port Vale to secure a 1-0 success.
The decisive moment came in the ninth minute after Richard Duffy fouled Ivan Toney 30 yards from goal on the right flank.
Hourihane curled in a terrific left-foot free-kick which eluded everyone in a crowded goal-mouth before the ball flashed inside Jak Alnwick's right-hand post.
Vale got back into the game by forcing a series of corners and Ajay Leitch-Smith's shot forced a fine diving save from Adam Davies in the 25th minute.
And Leitch-Smith fluffed a great chance to equalise seven minutes before the break, shooting straight at Davies with a weak half-volley after being sent clear by an excellent pass from Anthony Grant.
Adam Hammill cut in from the left flank to fire narrowly wide in the 55th minute as the visitors went in search of a second goal.
But Vale were forcing the pace and should have levelled in the 61st minute when Sam Foley fired high and wide from eight yards with the goal at his mercy.
Duffy, Carl Dickinson, Louis Dodds and Ben Purkiss all went close in the closing stages as Barnsley failed to kill off the game, but they still sealed all three points to remain in the Sky Bet League One play-off places.