Barnsley manager Poya Asbaghi revealed his side put extra effort on the training ground to work on their set-pieces in the build-up to the win over the Robins.
The hosts exploited Bristol City's Achilles heel by scoring twice from corners, both from the same side just 11 minutes apart.
City failed to deal with the first delivery which went through a body of players before ricocheting off a Barnsley man into the feet of Carlton Morris who scored from close range. The second saw towering defender Michal Helik unmarked as he beat Robbie Cundy to the ball to head past the helpless Dan Bentley in the City goal.
Abaghi conceded after the contest that working on attacking set-plays was their "main focus" in an attempt to take advantage of City's glaring weakness.
"We scored from two corners which were finally the decisive part of the game for us. It is important for us if we are going to stay up that we are not only scoring from counter-attacks or open play," he said.
“Before this game our main focus was the set pieces because we knew that Bristol City is a team we could use spaces in a good way against. I am happy that focus paid off. We have to keep using it.”
The Tykes haven't been a particularly proficient side from set-pieces this season with their double against the Robins taking their haul from those situations to just six. Barnsley goalkeeper Brad Collins also summed up City's inability to defend crosses by adding: "We scored two great goals from set-pieces which we haven’t done a lot this year so we’re thrilled with that."
City have conceded 13 goals from set-pieces, only Reading have shipped more in the Championship, and the danger is clear that not only are the vulnerabilities well known but teams are continuing to target them in those areas with Steve Bruce's West Brom the visitors to Ashton Gate on Saturday.
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City manager Pearson was eager to point out that the same group of players that played Blackburn defended their box well and instead criticised the sloppy mistakes his side made.
Deflated after the whistle, he said: "It's the same players who played at the weekend who did it (defend ser-pieces) very well so our inconsistencies come back to haunt us and that remains a problem for us this season.
"All I'm saying is that we perform well at the weekend and there's no reason why we couldn't perform in the same sort of way. The way we started the game was sloppy and we were very, very wasteful with the ball."
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