Boro had taken a sixth-minute lead courtesy of Ashley Fletcher's second league goal of the campaign.

Bees boss Frank said: "Sometimes stats don't tell the whole story. We knew it was coming and it would be nice to get a win against one of the big teams and this was like a big win.

"It was about time. Boro is a top club and one of the best in England. We knew it would be difficult and we are very pleased with the way we did it. I am proud of the boys, they did very well.

"I am not being arrogant but we knew we could do well because we are good on the ball. We are on a good run, we are a good team, we have big confidence and big dreams, but the most crucial thing is to concentrate every day.

"We controlled the game, didn't give it away too easily and had opportunities. I am very pleased with the way we handled the last 15 minutes when they went long.

"We are normally a weak side, so all the experts say, but we were definitely not weak today. We showed real character."

The defeat was damaging for Middlesbrough in the race for automatic promotion.

Tony Pulis' side are 12 points off a top-two spot, with Norwich, Leeds and Sheffield United all recording victories.

Pulis was criticised by supporters for taking off striker Britt Assombalonga and replacing him with full-back George Friend when Middlesbrough led – with fans directing sarcastic chants his way.

But the Boro boss was also disappointed with the performance of referee Jeremy Simpson for not giving any of three decent penalty shouts, while Fletcher could have headed in a second.

Pulis said: "We are disappointed. They are a good side, three or four players would be in any team in this division. We got a great start, we should have had a definite penalty.

"I will go and see him (the referee), I don't normally. He has booked Jonny Howson for diving and the lad has caught him. I don't know how they get it so wrong sometimes.

"We should have had three definite penalties. At home you think you might get them, or at least one.

"It wasn't a popular decision (taking Assombalonga off). I didn't think Britt looked sharp, quite at it like he has been. The Fletcher header I expected Britt to move and tap in, it went past him.

"The whole squad are together, they are in it together. If I bring anyone off I think it is best for team.

"If I messed up, I messed up. People can look at my decisions and say I have made the wrong decision and I have no problem with that."

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