Efe Sodje was sent off in the third minute of stoppage time to complete a miserable day from Huddersfield,Skipper Sodje was given the run around by Barnsley striker Barry Conlon who inspired a first win in seven matches.
The Tykes had only won once in eight games this season but the form of midfield playmaker Stephen McPhail gives Barnsley hope of a rapid climb up the table.
Former Leeds United star McPhail showed Premiership vision and passing and Huddersfield failed to contain him.
Sodje was in trouble against Conlon right from the start and never looked at ease.
Conlon hit the opener and Huddersfield defender David Mirfin scored an own goal as Barnsley had the points in the bag after just 20 minutes.
Sodje's weak backheader after just five minutes let in Conlon but the big striker blasted over.
Robbie Williams supplied the opener with a throughball Sodje failed to cut out and Conlon charged through to fire home in the 10th minute.
Barnsley doubled the lead just 10 minutes later when Williams and Michael Chopra caused problems for the Huddersfield defence and Mirfin blundered by heading past the advancing Ian Gray.
Barnsley completely dominated the first half and could have had more goals.
Nicky Wroe's powerful shot was tipped over by Gray before Williams crossed for Conlon to head wide at the back post.
Sodje's central defensive partner Steve Yates was also exposed for pace when Chopra left him standing but Gray raced to the rescue.
Huddersfield boss Peter Jackson replaced Yates with winger Junior Mendes and switched from three at the back to a 4-4-2 formation for the second half.
Huddersfield improved and Mendes went closest with a curling drive just past the far post though a comeback never looked likely.
Conlon was replaced in the 90th minute just before Sodje was sent off for an elbow on Wroe which completed the nightmare for the Town captain.