MAMADOU Thiam’s long-range double sent Oxford United on the way to a sobering opening-day hammering by a powerful Barnsley side.

The hosts, relegated from the Sky Bet Championship in May, looked a class above their opponents even before the midfielder’s first-half brace.

Both were sweetly-struck low drives which fizzed into the same corner of Simon Eastwood’s net, putting the Tykes in charge.

United, who also lost Samir Carruthers to a knee injury in a miserable first half, struggled all over the pitch.

And the visitors’ fate was sealed when they were unable to cash in on a decent spell midway through the second half, before Brad Potts made it 3-0.

Victor Adeboyejo took advantage of some more generous defending late on, to complete the rout.

On this evidence, anyone finishing above Barnsley this season will win automatic promotion, while United still have plenty of work to do if they want to be in the mix.

Boss Karl Robinson handed competitive debuts to four summer signings – Jamie Mackie, Carruthers, Luke Garbutt and Tony McMahon – in his starting line-up.

It took Barnsley just 30 seconds to give a hint of their threat, as Thiam skipped past McMahon and pinged in two dangerous crosses which were cleared by Curtis Nelson.

Within another minute Kieffer Moore, who was imperious in the air throughout, steered a header just wide from Daniel Pinillos’s free-kick.

United were unable to shake off their air of defensive vulnerability, with Barnsley finding space at will when they came forward.

It took a terrific block by a combination of Luke Garbutt and goalkeeper Simon Eastwood to prevent Moore converting Thiam’s delivery.

United smuggled the ball behind for a corner, which was delayed while Carruthers got treatment on a knock.

It was serious enough to force the midfielder off – a real blow after a pre-season where the squad had come through without any issues.

The game continued while Sam Smith was readied from the bench and during the brief period playing with ten men, United conceded.

Not for the first time in the opening 20 minutes there was space to exploit in central midfield, which Thiam ruthlessly exploited with a low 20-yard effort which flew into the far corner.

Once introduced, Smith showed a flash of pace to latch on to Mackie’s pass and find Jon Obika, whose low effort from the edge of the box was Barnsley goalkeeper Adam Davies’s only save of the half.

Instead, Barnsley continued to impress.

Quicker, stronger and sharper than their opponents, the Tykes created chances almost every time they went forward.

And it was 2-0 on the half-hour mark. Josh Ruffels was ambushed by three red-shirted players in the centre circle and Barnsley broke with Brad Potts.

United appeared to have stemmed the attack when the midfielder was forced to turn back, but his pass found Thiam, who lashed a first-time effort from the edge of the box which beat Eastwood again.

The contest remained one-sided up to half-time, with the visitors unable to change the flow of the game.

Barnsley’s front two of Moore and Tom Bradshaw won everything in the air and their midfield found space easily.

The second half began in the same vein, with the home side on top and in search of a third goal to kill the game off completely.

United were in dire need of something to go their way and on the hour they should have pulled a goal back.

Obika was put through by Curtis Nelson’s powerful header, but after getting into the box he fell before getting a shot away.

In the context of the game, it was a terrible miss.

A mistake at the other end almost made it 3-0 on 68 minutes.

Eastwood kicked straight to Kenny Dougall, who first-time effort from the centre circle sent the goalkeeper frantically retreating to get fingertips on the ball and divert it for a corner.

Rob Hall injected some life from the bench and his swerving 25-yard shot almost caught out Davies, who was relieved to palm the ball round the post.

But from the corner, Barnsley broke and made the game safe when Mowatt teed up Potts to smash the ball home.

There was still time for things to get worse, with Adeboyejo adding a fourth from close range late on to complete United’s misery.

Barnsley (4-4-2): Davies, Cavare, Pinnock, Lindsay, Pinillos, Potts, Dougall, Mowatt (McGeehan 79), Thiam (Moncur 70), Moore (Adeboyejo 82), Bradshaw.

Unused subs: Walton, Jackson, Isgrove, Bird.

Booked: None.

Oxford Utd (4-2-3-1): Eastwood, McMahon, Nelson, Dickie, Garbutt, Brannagan, Ruffels, Mackie (Whyte 82), Henry (Hall 63), Carruthers (Smith 21), Obika.

Unused subs: Stevens, Mousinho, Raglan, Norman, Whyte.

Booked: None.

Referee: Ross Joyce.

Attendance: 12,820 (1,279 visitors).