The Super Reds lost 3-2 at Portsmouth, having led 2-1 on 85 minutes, and still need three points from the last two games to secure a play-off place.
Devante Cole ended his goal drought with a fifth-minute opener but the Portsmouth levelled almost instantly. John McAtee restored the lead after the break then conceded a penalty late on which was converted before an 89th-minute winner.
The Reds played well for the majority of the game but came away empty handed as Portsmouth secured the league title.
Barnsley remain fifth, four points clear in the top six. They travel to eighth-placed Blackpool on Saturday, who can still catch them, then host mid-table Northampton on the final day.
The reds made two changes from Saturday’s home draw with Reading. Barry Cotter and full debutant Conor Grant came in for Corey O’Keeffe and the injured Jon Russell. Youngster Theo Chapman was on the bench with Luca Connell still out.
Barnsley started well with Adam Phillips volleying a tough chance wide. Cole ended a 14-game goalless run with his 18th of the season. Grant found Cotter on the right of the box and his low scuffed cross was turned in from close range.
The equaliser came two minutes later when Tino Anjorin’s pass after a good move deflected off Earl to Kusini Yengi who smashed in a powerful 15-yard shot past Liam Roberts.
Anjorin then shot just wide from the left of the box. But Barnsley played well for the remainder of the half.
John McAtee’s weak 20-yard shot was easily saved after a good Jordan Williams pass. McAtee then had another even better chance as Herbie Kane’s superb pass put him clean through on goal but he was denied by goalkeeper Will Norris.
In the second half, Sean Raggett headed over from a corner then Yengi dragged a shot wide from the edge of the box in space after Callum Lang flicked on a long pass.
Josh Earl’s long-range shot was easily saved but the Reds retook the lead just before the hour-mark when Nicky Cadden brilliantly sprinted deep into the home half and played through McAtee to supply a cool one on one finish.
Portsmouth’s Lee Evans shot just over from 25 yards then Marlon Pack blazed over a free-kick.
Portsmouth were awarded a penalty when McAtee stupidly brought down substitute Christian Saydee on the right of the box and Colby Bishop converted from the spot.
Four minutes later Conor Shaughnessy beat substitute McCart in the air and headed in from close range from a corner that McCart had conceded.
Substitute Fabio Jalo could not connect with a Cadden cross in injury-time.
Barnsley (3-5-2): Roberts; Williams, de Gevigney, Earl; Cotter (O’Keeffe 73mins), Phillips, Grant (McCart 88, Kane, Cadden; Cole, McAtee (Jalo 88)
Unused: Killip, Cosgrove, Marsh, Chapman.
Yellow cards: De Gevigney.
Goals: Cole 5, McAtee 59.
Portsmouth (4-2-3-1): Norris; Swanson (Rafferty 31mins), Shaughnessy, Raggett, Ogilvie; Evans (Saydee 80mins), Pack; Kamara, Anjorin (Lang HT), Whyte (Lane 61), Yengi (Bishop 61).
Unused: Macey, Moxon.
Yellow card: Lane.
Goals: Yengi 7, Bishop (pen) 85, Shaughnessy 89.
Another good performance but nothing to show for it and the reds now travel to play-off chasing Blackpool on Saturday.
COYR
