Peterborough United clung on for three vital points from a tense fixture against Barnsley with skipper Tommy Rowe popping up with the winner four minutes from time at London Road.
Dwight Gayle was denied by former Posh keeper Luke Steele inside the first three minutes as Lee Tomlin flicked the ball into his path with the home side making the most of the early running.
Olejnik superbly tipped over a close-range effort from Craig Davies after Mark Little was caught out of position down the Posh right. Posh got their noses in front on 29 minutes and it was a crisp free-kick from Michael BOSTWICK, who celebrated the birth of his baby boy in style, firing past Steele.
Joe Newell then went on a mazy run, which took out two defenders, but as he cut inside the centre back, he saw his shot blocked. Steele then denied Newell whose low right-foot effort from 20-yards skidded along the floor.
On 37 minutes, Posh wanted a spot-kick as Newell was barged over in the box, but referee Darren Drysdale waved away the protests. Steele then denied Tomlin from long-range, the striker's swerving effort grabbed at the second attempt by the inspired custodian.
On 44 minutes, a free-kick from Tom Kennedy took a nasty deflection, but somehow goalkeeper Olejnik was able to keep the effort out.
Boyd saw an effort go well wide on 51 minutes after a throw-in from the right. Olejnik produced a fine stop to deny Dagnall on 63 minutes as he waltzed through the Posh defence, who were tiring under the pressure.
Dagnall then shaved the outside of the post with a curler from 30-yards as Posh clung on. Dawson was next to try his luck, but his 20-yarder went just past the post.
Danny Swanson replaced Newell on 75 minutes. Barnsley got themselves level in controversial fashion on 77 minutes as Harewood's strike was touched home in the six-yard box by Dagnall, who appeared to touch the ball from an offside position. After a long consultation between the referee and the assistant referee, Mr Drysdale gave the goal.
However, on 86 minutes, Posh got themselves back in front, completely against the run of play as skipper Tommy ROWE skipped inside two challenges and fired low past Steele and into the back of the net.
The referee angered the Posh fans when he ignored an injury to Brisley and allowed Barnsley to play on and then win a free-kick to the annoyance of the Posh faithful.
Final Score: Posh 2-1 Barnsley
Posh: Olejnik, Brisley (sub Knight-Percival 90min), Zakuani, Bostwick, Rowe, Little, Ferdinand, Boyd, Newell (sub Swanson 75min), Tomlin (sub Kearns 88min), Gayle. Unused subs: Day, Alcock, McCann, Gordon.
Barnsley: Steele, Golbourne, Dawson, O'Brien (sub Lazarus 83min), Davies (sub Harewood 66min), Perkins, Dagnall, McNulty, Cranie, Kennedy, Stones. Unused subs: Alnwick, Foster, Done, Cywka, Greening.
Attendance: 7,339 (932 Barnsley fans)