You now have to go back 12 matches to their previous win in the second tier - on September 30, 2017.
The wait for three points at Oakwell at this level goes back much further to September 1, 2012, a sequence of 13 league games.
Few episodes can have been as grim as this, more especially in a final half hour when the hosts simply imploded in inept, tactically reprehensible fashion which saw the visitors score three times and threaten at a fair few more.
The upshot is that Markus Schopp's Reds are now winless in eight matches and their poor start to the campaign has reached its nadir. A huge game against Millwall now awaits.
Without the touchline assistance of Jo Laumann and Tonda Eckert, who have both copped bans following the recent fracas at Stoke, Schopp looked a man running out of friends among the Oakwell faithful, who let their feelings known in no uncertain terms at the final whistle with a cascade of boos.
Some 130 days after last visiting Barnsley with Swansea, new Nottingham Forest manager Steve Cooper comprehensively outflanked his opposite number with the introduction of Lewis Grabban and Forest's switch to a 4-2-3-1 formation on the hour totally changing the game and spooking Barnsley.
Grabban provided the initial throughball which led to a leveller from Philip Zinckernagel, who tapped home on 61 minutes after being found by Brennan Johnson.
Seven minutes later, Johnson - who ran riot on the restart - undressed the hosts down their left and converted with Barnsley again opened up. An offside flag had initially been raised, but referee Geoff Eltringham overuled him, seemingly after the throughball came off Liam Kitching.
Grabban got the goal he deserved from close range eight minutes from time after Alex Mighten, another replacement, skinned Jasper Moon.
It was hard to fathom that the first half had actually seen Barnsley take the lead and look fairly comfortable, going ahead courtesy of 20th-minute penalty from Cauley Woodrow.
The game was not particularly going anywhere until crafty play saw him momentarily give Tobias Figueiredo the slip and the flustered Forest defender blatantly tugged the short of the Reds captain for an obvious penalty, which was dispatched with aplomb.
On the night, Woodrow looked the sole offensive outfield player who seemed to know what he was doing, but unfortunately others were not on his wavelength.
Given the fact that both sides had mustered a collective total of two wins from 18 league matches thus far this term, the smart money was always on this never being classic. It certainly wasn't from a Barnsley perspective.
It was a game when the margins were always likely to be fine and the small details were priceless and it was Forest who erred first. Barnsley were ultimately guilty of greater footballing crimes and went to pieces in the second period.
The cinema talk this week has revolved around the new James Bond film entitled 'No Time to Die.' In truth, all Barnsley supporters wanted to see was a licence to kill in the final third for a Reds side who boasted just six goals this term ahead of the game, with only four players managing to find the net so far in 2021-22.
It was not in evidence, despite the lifeline provided by Woodrow. The supporting cast was pretty non-existant.
Barnsley started with a 3-4-2-1 formation, with the recalled Clarke Oduor and Dominik Frieser just behind Woodrow, while Jordan Wiliams were promoted to the starting line-up ahead of kick-off due to an injury for Josh Benson, originally named in the side.
The presence down the right of Djed Spence, up against Williams, was the main outlet for Forest, who broke quickly when the chance arose, without troubling Brad Collins.
A cross from Spence seemed destined for Johnson in front of goal, only for Liam Kitching to make a fine clearance, while on the other flank, Joe Lolley fired a crisp low shot wide after Forest broke after Callum Styles’s error.
A juicy challenge from Zinckernagel on Michal Helik cranked up the heat ahead of the break and it was that sort of night where tension was palpable on a big evening for both sides, with Forest’s contingent in the West Stand including former Barnsley chief executive officer Dane Murphy and ex-club secretary Taymour Roushdi.
Woodrow saw a shot blocked early in the second half from Brice Samba, but aside from a late header from substitute Aaron Leya Iseka, all the action was at the other end as Forest laid siege and cut through Barnsley at will.
Deeply worrying times for Barnsley and Schopp.
Barnsley: Collins; Moon, Helik, Kitching; Brittain, Palmer (Leya Iseka 72), Styles, J Williams; Frieser (Adeboyejo 65), Oduor (Gomes 80); Woodrow. Substitutes unused: Walton, B Williams, Sibbick..
Nottingham Forest: Samba; Worrall, Figueiredo, McKenna; Spence, Yates, Garner (Colback 71), Lowe; Zinckernagel (Grabban 60); Johnson, Lolley (Mighten 75). Substitutes unused: Horvath, Bong, Taylor.
Referee: G Eltringham (Tyne and Wear).