Barnsley's run of four straight home wins came to an end with a 2-0 loss at home to second-placed Swansea City.
The visitors had been second best in the first half but took the lead just before the break then doubled it early in the second half after a terrible mix-up between Mads Andersen and Michal Helik.
The Reds are now tenth, six points off the play-off places, while they have lost their last two league games against the current top two.
Valerien Ismael made two changes from the team that beat Tranmere Rovers in the FA Cup last week. Jack Walton returned in goal while Victor Adeboyejo came in for Dominik Frieser. New signing Carlton Morris started on the bench.
The first chance of the game fell to Adeboyejo in the 11th minute when away defender Ben Cabango slipped over and the striker ran onto a Herbie Kane pass then blasted over from just outside the box when he could have passed to Cauley Woodrow on his right.
Adeboyejo tested the goalkeeper with a powerful shot from the right of the box at a very tight angle which was beaten away and, from the resulting corner, Conor Chaplin saw a shot blocked.
At the other end, Walton had to claw away a long throw by Connor Roberts which Jake Bidwell tried to get on the end of. A corner from the right then seemed to hit Andre Ayew and go wide from five yards out.
Styles tested goalkeeper Freddie Woodman with a low 25-yard shot in the 39th minute but it lacked power and was easily gathered.
But the visitors took the lead in first half injury-time when another Roberts long throw from the right was met by Cabango whose impressive header looped into the top left corner. Michael Sollbauer had been left marking Sollbauer and ex-Red Korey Smith but the former was free to nod the ball into the net.
The Swans were on top early in the second half, with Roberts firing a vicious volley just wide of the right post from outside the box.
It was 2-0 on 56 minutes when a hopeful header forward should have been cleared but Andersen headed it into Helik as they bumped into each other then the ball rolled to Jamal Lowe who went clean through on goal and fired past Walton.
Ismael brought on Morris for his debut and Romal Palmer, with Conor Chaplin and Herbie Kane taken off.
Woodrow headed wide from a cross by Brittain who almost scored his first Barnsley goal with a sensational 25-yard strike but Woodman did well to claw it out of the top left corner. Brittain then beat a man on the edge of the and fired over.
At the other end, Walton touched wide a right-wing free-kick by Roberts which had looked destined for the top right corner.
Barnsley (3-4-3): Walton; Sollbauer (Sibbick 84mins), Helik, Andersen; Brittain, Mowatt, Kane (Palmer 63), Styles; Chaplin (Morris 63), Woodrow, Adeboyejo (Thomas 84). Unused: Collins, Oduor, Schmidt, Moon, Frieser. Yellow cards: Andersen.
Swansea (3-5-2): Woodman; Naughton, Cabango, Guehi; Roberts, Smith, Fulton, Grimes, Bidwell; Lowe, Ayew. Unused: Hamer, Latibeaudiere, Manning, Byers, Dhanda, Cooper, Routledge, Garrick, Cullen.. Goals: Cabango 45+1, Lowe 56.
  • 7:46pm
    The Reds get the game underway
  • 7:48pm
    3 An unsettled start to the game with both sides knocking it long with little success.
  • 7:49pm
    4 Callum Brittain concedes a corner on the Reds' right.
  • 7:50pm
    4 Matt Grimes and Jamal Lowe work a neat short corner and the latter lays it off to be crossed low into the box, but it's cleared.
  • 7:52pm
    6 Conor Chaplin plays a through ball for Victor Adeboyejo to chase, and the forward forces a mistake from Freddie Woodman who clears it into the stand. Barnsley do little with the resulting throw.
  • 7:54pm
    8 Herbie Kane's long throw from the right is cleared. Conor Chaplin takes a crack from the edge of the box but it's blocked.
  • 7:57pm
    10 There have been a fair few free kicks in non-threatening positions in the middle of the park. Herbie Kane takes the latest from the left, aiming towards Mads Andersen, but the defender gives away a foul as he challenges.
  • 7:57pm
    11 Victor Adeboyejo blazes over after Ben Cabango slips following Herbie Kane's clip over the top. First real chance.
  • 8:01pm
    15 Matt Grimes lofts it into the box from a throw-in on the visitors' left, but it's cleared and Mads Andersen fires it away down the line.
  • 8:05pm
    19 A long throw from Connor Roberts puts Jack Walton under pressure, but the 'keeper manages to punch clear ahead of Jake Bidwell. Victor Adeboyejo forces a good save from a tight angle as the Reds break upfield and the home side get a corner.
  • 8:07pm
    20 The Reds get multiple chances but narrowly miss each time. As Callum Styles lofts it back into the box, it's a little too high for Cauley Woodrow and goes out for a goal kick.
  • 8:11pm
    24 Matt Grimes hits an in-swinging corner from the right which Marc Guehi meets, but he gives away a goal kick.
  • 8:12pm
    26 Herbie Kane with a long throw from the left but he can't beat the first man. Callum Brittain then gets it 25 yards out and hits a quick cross into the box, but no one's there to meet it and it rolls out.
  • 8:16pm
    29 Victor Adeboyejo lays the ball off for Callum Brittain on the edge of the box and receives the return, playing in Conor Chaplin whose cross from the right is optimistic. No one gets there and it's out.
  • 8:17pm
    31 Another long throw from the right by Connor Roberts causes a few problems, with Michal Helik slicing a clearance well up in the air. Jack Walton is allowed to collect and gratefully does so.
  • 8:23pm
    36 Another lull in the game. Barnsley's best outlet has probably been Victor Adeboyejo, who's acted as a target man and is holding play up well. However, he could have played Cauley Woodrow in for the Reds' first chance.
  • 8:24pm
    38 Jamal Lowe gives away a free kick as he tries to dribble through but fouls Mads Andersen in the box.
  • 8:25pm
    39 Callum Styles is able to take a touch on the edge of the box, but his strike is right down the middle for Freddie Woodman who collects.
  • 8:26pm
    40 Victor Adeboyejo gives away a free kick in a good position for the Swans to play it into the box from the left.
  • 8:32pm
    45 Cauley Woodrow is back defending after Matt Grimes' set piece from the halfway line is sent to the right of Jack Walton's goal and played into the centre. The striker heads it clear well.
  • 8:32pm
    45+1 Ben Cabango scores for Swansea.
  • 8:33pm
    45+1 The centre-back got his head to a Connor Roberts long throw from the right. It looped into the far corner.
  • 8:50pm
    The visitors get the second half underway
  • 8:52pm
    47 Kyle Naughton blazes over on the half volley after a Jake Bidwell long throw is partially cleared to the edge of the box.
  • 8:54pm
    48 A mix up between Michal Helik and Mads Andersen as Jay Fulton heads the ball across goal following a blocked Andre Ayew cross from the left. Andersen headed it into the back of his centre-back colleague, but then cleared it more successfully on the second attempt.
  • 8:57pm
    52 Michael Sollbauer concedes a corner on the right after Jake Bidwell's throw. Connor Roberts swings it in and it's cleared for another on the opposite side.
  • 8:58pm
    53 Connor Roberts with a decent effort after Cauley Woodrow clears the corner. Roberts hit it on the half volley from just outside the box and it flew past the near post.
  • 9:00pm
    55 Mix-up between Mads Andersen and Michal Helik leads to Jamal Lowe getting clear and slotting it past Jack Walton.
  • 9:00pm
    55 Jamal Lowe.
  • 9:06pm
    60 Corner for the Reds as Callum Brittain's cross from the right is blocked. Barnsley look to be bringing two subs on including debutant Carlton Morris.
  • 9:07pm
    61 Herbie Kane and Conor Chaplin.
  • 9:07pm
    SUB ON
    61 Romal Palmer and Carlton Morris.
  • 9:10pm
    65 Romal Palmer's shot from the edge of the box is blocked as Alex Mowatt dummies a pass and allows the midfielder to shoot. The resulting corner is eventually headed wide by Mads Andersen.
  • 9:16pm
    69 Another long throw from the right from Connor Roberts is laid off by Jamal Lowe for Andre Ayew and the Swansea forward has a penalty shout turned down as he goes down on the edge of the box. Then, a clash between Ben Cabango and Jake Bidwell lets Callum Brittain through on the Reds' right, but he can't do anything with the opportunity.
  • 9:17pm
    72 Callum Brittain with a great strike after a corner is cleared for the defender to try his luck from 30 yards. His powerful, swerving effort is tipped past the post by Freddie Woodman.
  • 9:24pm
    78 Carlton Morris is fouled as he tries to break down the left and Alex Mowatt hits the ball into the box from the free kick. It's cleared for a corner which the Reds take short and Romal Palmer is tripped for a free kick from a decent position on the right.
  • 9:26pm
    81 Callum Brittain fires over the bar with his second decent attempt of the second half. This time he's just inside the box, right of goal, Carlton Morris with a good bit of skill on the left, laid the ball off for Callum Styles who played in Brittain.
  • 9:28pm
    83 A Connor Roberts free kick on the left swings towards Jack Walton's far post, but the 'keeper tips it wide.
  • 9:28pm
    84 Victor Adeboyejo and Michael Sollbauer.
  • 9:29pm
    SUB ON
    84 Luke Thomas and Toby Sibbick.
  • 9:32pm
    87 Carlton Morris wins a corner on the left. Romal Palmer swings it in but it's headed clear by Andre Ayew.
  • 9:35pm
    90 Toby Sibbick with an impressive surge from the centre of the pitch, wins a throw in a good position on the left. It's worked out to Alex Mowatt whose effort is blocked for a corner.
  • 9:35pm
    3 minutes added time
  • 9:38pm
    90+3 Jamal Lowe for not allowing Callum Styles to take a free kick.
  • 9:39pm
    FULL-TIME: Barnsley 0, Swansea City 2. A tough one for the Reds.