Barnsley registered their first away win of the season with a 3-1 success over Millwall at The Den.

Tom Bradshaw put the visitors ahead on 40 minutes but Millwall levelled before half-time with a penalty by Lee Gregory who had been brought down by the recalled Matty Pearson. Head coach Paul Heckingbottom was furious with the decision and was sent to the stands after debating it with the officials.

But his side won the match without him on the sidelines as Bradshaw got his second – from a second assist by the impressive Harvey Barnes – then Mamadou Thiam sealed the victory with a penalty won by fellow substitute Jared Bird.

Heckingbottom made three changes from the side that drew with QPR on Tuesday. Pearson replaced Zeki Fryers at left-back and Bradshaw came in for Ike Ugbo. Cameron McGeehan made his first Reds start in place of George Moncur who dropped out of the squad but is not injured.

In the fourth minute, Millwall should have taken the lead when former Barnsley transfer target Gregory went clean through after bundling the ball past Liam Lindsay in the Reds box, but Adam Davies made a good one-on-one block.

Barnsley gradually settled into the match and, after McGeehan fired wide with a low 25-yarder, Bradshaw's header from a Barnes cross was easily gathered by home goalkeeper Jordan Archer then Brad Potts nodded Adam Hammill's cross well wide.

Barnsley's first clear cut chances came in the 39th minute when Archer badly spilled a cross to McGeehan who had two efforts blocked by a combination of defenders and the goalkeeper who then parried away Bradshaw's effort before finally claiming the ball.

Archer was beaten a minute later when Bradshaw flicked in from close range after Barnes fired in a low cross from the left. The lead lasted just seven minutes as Gregory sent Davies the wrong way from the spot having gone down after a last-ditch tackle from Pearson following the Millwall striker once again outmuscling Lindsay.

The home crowd wanted a red card but Pearson was only booked while Heckingbottom clearly thought his left-back had won the ball as he marched straight onto the pitch after the half-time whistle and remonstrated with referee Oliver Langford and his officials for several minutes. Heckingbottom was then sent to the stands two minutes after the interval after coming back into the dugout when the referee had allegedly told him he would have to watch the second half from the stands. 

Millwall's Aiden O'Brien and Jed Wallace both had long-range efforts which were straight at Davies, and it was the Reds who went 2-1 up. Barnes burst into the home box from the left wing and sent in another low cross which was tapped into the gaping net at the back post by Bradshaw.

The dangerous duo were both brought off on 72 minutes to be replaced by Ryan Hedges and Thiam. Millwall almost made it 2-2 but Davies got down well to his left to catch a Steve Morison header from a left-wing cross.

Potts then could have made it 3-1 after a fantastic cross by Thiam but he headed straight at Archer from close range on the left. The third goal eventually came from the penalty spot as Thiam sent Archer the wrong way with a spot-kick into the bottom right corner. Bird, another substitute, had won it for a trip after a jinking run into the box following a good burst forward by Thiam.

Hammill almost made it 4-1 but he shot wide from the edge of the box after Thiam cut in from the left and pulled the ball back. Thiam then forced a save out of Archer from long range.