Oldham 1 (Yeates 78)
Reds 2 (Hourihane 30, Long 89)
Barnsley were almost cruelly denied a well deserved win at Oldham but up stepped Kevin Long on his debut to smash in a winner and give Barnsley all three points.
The Reds completely dominated and had to leave it late but it was certainly worth it, with Conor Hourihane's strike having been cancelled out by Mark Yeates' scruffy finish.
There was an early scare for the Reds as Poleon almost got in on goal but Davies read the long punt well to clear with a brave block outside the area on three minutes.
At the other end Watkins did well to beat the offside trap and a draw a block from Mills to hand Barnsley a corner on eight minutes. From the second phase of play after the corner, Hammill whipped in for Watkins at the far stick with the goal at his mercy but the cross was inches too high for a simple goal.
By 11 minutes the Reds were looking in control and their set-pieces causing mayhem in the Oldham box. Hammill saw an effort blocked on the edge of the box as the Reds looked to find the net to reward their dominance.
On 14 minutes Hammill went even closer as he bent a shot that deflected onto the outside of the post. It came after a good move from Isgrove and Toney saw the latter charge into the box from a Bree throw down the right.
Another set-piece on 17 minutes saw Ivan Toney glance a header just over as Hammill's vicious delivery from the right was perfectly placed for the striker to meet six yards out.
Somehow it stayed 0-0 on 19 minutes after Adam Hammill's shot was saved into the path of Watkins and his attempt on the rebound was blocked on the line from a Latics defender.
On half an hour finally Barnsley had their deserved lead. Adam Hammill kept a move down the right alive with some incredible skill, Bree then found Hourihane who struck first time from 20 yards and, via a deflection, it sailed into the top corner.
Yeates' desperate attempt to win a penalty with a dive didn't fool Mr Salisbury on 35 minutes and the winger was lucky he didn't see a yellow card for his theatrics.
Five minutes before the break Ivan Toney sent another header close after Hammill's cross was met by the striker, but he couldn't direct his attempt the right side of the post.
Remarkably Watkins was thwarted once again by a desperate block in the box. Bree delivered for Toney and his nod-down was struck on the turn by Watkins but Wilson was in the way.
After completely controlling the first half, there was almost a comical own goal in the dying seconds of the first half as White's nod back to Davies sailed past the 'keeper but, thankfully, wide.
Barnsley simply had to pick up where they left off and chances surely would fall their way again. There was almost a break on of three against one on 47 minted but Hammill was denied by a block from Dummigan.
Oldham could have made it 1-1 on 55 minutes although Adam Davies made a smart stop to deny Dummigan after the defender latched onto a placed pass into the box by Rasulo.
On 63 minutes it should have been 2-0 with Ivan Toney rattling the bar with a powerful header. Hammill was the architect with a fantastic run and cross from the left but Barnsley weren't rewarded for their brilliance once more.
Oldham made their second change on 66 minutes with Higdon coming on as the home side sought for a way back into the match.
The Reds broke on 68 minutes with Hammill once again proving the thorn in Oldham's side although his curling effort had Coleman scrambling, it sailed just wide of the far stick. From the break in play, Sam Winnall replaced Lloyd Isgrove for Barnsley's first substitution.
The wintry afternoon heated up when Ben Pearson's tackle on Liam Kelly wasn't well received by the home players and fans alike. The midfielder was awarded a yellow card.
Aidan White was replaced by George Smith after a solid debut that lasted 74 minutes.
The following Tykes thought Ivan Toney had broken the net for 2-0 on 77 minutes after he jinked his way into the box - his powerful drive hit the side-netting, though, for what would have been a great goal.
It was 1-1 on 78 minutes as out of nowhere the home side found the net. Mark Yeates latched onto a back heel from Poleon and his effort squirmed under Davies and trickled over the line.
Dummigan cracked a decent shot for what was a rare sight of Barnsley's goal with ten minutes left - the defender's shot dipped wide.
With Pearson galloping at goal on 88 minutes, Yeates kicked out at the midfielder in what was a cynical foul. Thankfully Barnsley made him pay with a winner as Smith launched the ball in, Jackson poked at goal with Coleman spilling into the path of Long who absolutely smashed it into the net.
Oldham: Coleman, Dummigan, B. Wilson, J. Wilson, Mills, Kelly, Dieng (Fulton 46), Yeates, Rasulo (Higdon 66), Philliskirk, Poleon.
Subs: Cornell, Eckersley, Brown, Winchester, Fulton, Fuller.
Reds: Davies, Bree, Mawson, Long, A. White (G. Smith 74), Hourihane, Pearson, Hammill, Watkins, Isgrove (Winnall 68), Toney (Jackson 84).
Subs: Townsend, Roberts, Nyatanga, Wabara.
Attendance: 4,300 (584 Reds)