Charlton 1 (Ajdarevic 90+1)
Reds 2 (M'voto 32, Kennedy 63)
Roared on by little less than a thousand Reds in the capital on a Tuesday night, Barnsley overturned Charlton 2-0 thanks to goals from two defenders in Jean-Yves M'voto and Tom Kennedy.
As was probably expected, the game commenced in a fast and frantic fashion with both sets of fans in good voice from the off.
Jordan Cousins fired in the first shot of the match on 11 minutes, causing Steele to scramble across his goal but the Charlton man's effort zipped wide from 22 yards.
The hosts went even closer on 28 minutes as Callum Harriott had a free header at the far stick but sliced his effort wide from six yards.
At the third time of asking as Charlton tried to chip the ball into the box, they eventually got a shot off from Jackson 18 yards out but it flashed over whilst the Reds appealed for a foul on Etuhu half an hour in.
However, having not tested Hamer, Barnsley took the lead when Jean-Yves M'voto powered a header at Jennings' in-swinging corner and into the bottom corner.
After picking up a knock in the first half, Kelvin Etuhu was replaced at the break by Jack Hunt at right-back. Poyet then flashed in the first attempt of the second period but it was always heading wide from 25 yards.
Charlton made their first change on 55 minutes as Reza Ghoochannejhad replaced Callum Harriott.
Stephen Dawson did the hard work of winning the ball but made a poor backpass that Sordell intercepted - thankfully, the former Watford man curled wide from just inside the area.
The game was starting to stretch and the pitch was tearing up with over an hour gone. Both teams were desperate to score the next goal.
On 63 minutes, the Reds doubled their lead through Tom Kennedy and it might have been fortunate but it didn't matter. Cywka showed incredible feet on the far left before feeding Kennedy and his cross left Hamer stranded and landed in the bottom corner.
Jack Hunt picked up a knock as the right-back curse struck once again, meaning a change of shape as Jacob Mellis came on with 74 minutes played.
Steele had to beat away a strike by Goochannejhad that the substitute really got hold of just inside the area a moment before the impressive Poyet was replaced by Ajdarevic on 78 minutes.
Jacob Mellis added another calming influence to midfield as Barnsley aimed to see the game out. Wiggins was withdrawn through injury meaning the Addicks had to play with 10 men for the final 10 minutes.
Just after the Fourth Official indicated five minutes of stoppage time, Charlton pulled one back through Ajdarevic after a block on the line denied Jackson. It gave the home fans hope and it was a nervous final few minutes for Barnsley.
The Reds held on and the travelling Tykes went crackers at the end to applaud their team.
Charlton: Hamer, Jackson, Dervite, Sordell, Harriott (Ghoochannejhad 55), Obika, Wood, Wiggins, Solly (Wilson 71), Cousins, Poyet (Ajdarevic 78).
Subs: Thuram-Ulien, Hughes, Morrison, Fox.
Reds: Steele, Kennedy, McLaughlin, M'voto, Cranie, Jennings, Dawson, Lawrence, Etuhu (Hunt 46 (Mellis 74)), O'Grady, Cywka.
Subs: Turner, Woods, Hassell, McCourt, Proschwitz.
Referee: Iain Williamson
Assistant Referees: Barry Holderness & Alan Dale
Fourth Official: Andy Davies
Attendance: 16320 (965 Reds)