The Tykes had goalkeeper Adam Davies to thank for stopping the rot with a brilliant injury time save when he tipped Ollie Watkins’ sizzling angled drive just past the post.
But Harvey Barnes and Tom Bradshaw both went close for the visitors in a frenetic last 20 minutes that could have seen the points go either way.
Neal Maupay was first to go close for the hosts after 16 minutes when he latched on to a ball over the top of the Barnsley back four, but his first touch let him down and keeper Davies pounced.
Barnsley defended deep but still posed a threat on the counter, with Mamadou Thiam’s pace on the flank and Bradshaw’s movement and constant threats.
Bradshaw almost broke the deadlock midway through the first half, but Daniel Bentley was quick off his line to quell the danger.
In a half of few clear-cut chances Romaine Sawyers might have done better with a glancing header that drifted just wide of the far post on the half hour mark.
Sawyers thought he had given the Bees the lead a minute later but his goal-bound effort from the edge of the box was blocked by his own player in Maupay, before ricocheting to safety.
Brentford left back Yoann Barbet got forward well and twice tested the Tykes goal as the half drifted to an end.
His first effort from long range deflected narrowly wide and his second lacked any real venom to seriously test Davies at the foot of his post.
Barnsley were content to sit and soak up the pressure from Dean Smith’s side and wait patiently to hit them on the break.
It nearly paid off on half time when Bradshaw broke free down the right, but his low angled drive found the side netting.
Barnsley were more adventurous after the break, but came close to going behind when Andy Yaidom forced a reflex stop from his own keeper after a slick Bees build up.
At the other end Barnes forced a brilliant save from Bentley when he thought he had ended the stalemate with a superb drilled free kick around the wall.
Barnsley grew into the game and Bradshaw volleyed over at the near post seconds after Joe Williams’ whipped cross was cleared at the back post by Nico Yennaris.
Brentford piled on the pressure in the final few minutes, but the Tykes were resolute at the back and continued to look dangerous on the break.
Barbet sliced wide with the clock counting down before Davies had the final say with that superb low stop to deny Watkins and frustrate home draw specialists Brentford.
Delighted Barnsley boss Paul Heckingbottom said: “We worked very hard for the point and I think we deserved it. After five defeats against teams who have had hardly any shots against us we were beginning to wonder what we’d done wrong.
“But we were a lot more ruthless and dogged defensively and that against a really good Brentford side. We’ve recruited players who don’t know this league but we haven’t panicked and we’ve kept working just as hard to try to improve every day. If not, this league will swamp you.”