Barnsley produced an exceptional performance as they thrashed fellow League One high-flyers Peterborough United 4-0 away from home. 

The hosts should have taken the lead through an early penalty but Adam Davies saved from his former Oakwell team-mate Ivan Toney then, minutes later, George Moncur put the visitors ahead before Brad Potts’ superb 25-yard strike made it 2-0 on the stroke of half-time. 

Potts added another from outside the box early in the second half then substitute Jacob Brown completed the rout in injury-time. 

The result means Peterborough stay second while Barnsley are up to fourth, two points behind the Posh with a game in hand. 

Head coach Daniel Stendel made five changes from the team who started the 1-1 draw on Tuesday night with bottom club Plymouth Argyle, after which he was very frustrated.

Liam Lindsay replaced Adam Jackson at centre-back while Ryan Hedges, Mamadou Thiam and Victor Adeboyejo dropped to the bench with Potts, Moncur and Mike Bahre coming in. There was also a first league appearance for teenage left-back Ben Williams with Dani Pinillos injured. 

Barnsley started on top but home goalkeeper Aaron Chapman saved easily from Kieffer Moore, Potts and Moncur. But it was the hosts who should have taken the lead when the referee did not rule that Davies had fouled Toney when through one-on-one but did think Dimitri Cavare had tripped Joe Ward in the box.

Davies dived low to his left to impressively save Toney’s penalty, then, within two minutes, Moncur turned in the Peterborough six yard box and fired home after Bahre’s cross from the right of the box was deflected to him. 

Moore almost made it 2-0 when he fired just wide of the bottom right corner then came lose again when he was put through after superb work by Potts but Chapman produced an outstanding one-handed save. 

Peterborough boss Steve Evans felt he had to make a change on 26 minutes as Barnsley were dominating, going to 4-4-2 from 4-4-1-1 by bringing midfielder Jamie Walker off for top-scorer and striker Matt Godden who almost levelled within seconds but headed a Marcus Maddison free-kick wide.

Moore had to come off injured, with young striker Jacob Brown replacing him as the lone frontman.  Toney headed another free-kick wide then Jason Naismith headed another one straight at Davies, as Peterborough dominated in the air in the Barnsley box. 

But it was the visitors who got the second goal in first half injury-time, with Moncur tapping a free-kick to Potts who brilliantly smashed into the top right corner from 25 yards. 

Cavare should have made it 3-0 two minutes after the interval after running on to a sensational throughball by Potts but he blazed over the bar from ten yards out on the right of the box. 

Davies easily saved an attempted Marcus Maddison lob while, at the other end, Bahre curled over from outside the bar after a skilful run. 

The third goal came after an hour when Moncur ran down the left wing then cut inside before finding Potts who placed an excellent 18-yard shot into the bottom left corner. 

Mark O’Hara headed straight at Davies from a Darren Lyon cross after Ethan Pinnock lost the ball then Alex Mowatt cleared off the line after Godden headed a corner. 

Moncur got his third assist of the day in the 93rd minute when he finished off a fine move by playing in Brown who brilliantly cut past a defender then fired into the bottom left corner. 

Barnsley: Davies; Cavare, Lindsay, Pinnock, B Williams; Potts (Hedges 78mins), Dougall, Mowatt, Moncur; Bahre (Thiam 89); Moore (36).  Subs: Walton, McGeehan, Jackson, Adeboyejo.  Yellow cards: Cavare, Lindsay.  Goals: Moncur 14: Potts 45+1, 59; Brown 90+3

Peterborough : Chapman; Naismith, Tafazolli, Bennett, Daniel (Lyon 54mins);  Maddison (Reed 65) ; Woodyard, O'Hara, Ward; Walker (Godden 27); Toney. Subs: Tyler, Dembele, Cooke, Cummings. Yellow cards: Bennett, Reed.