The result leaves the Tykes a point and a place adrift of safety but head coach Struber saw plenty of reasons to cheer.
Struber said: "I am very proud of my team. We played very well against a big opponent. This is a big opponent, Huddersfield, and they have a big budget.
"We created a very good game. We made the next step in my style on the ball.
"I think this is the next very important step on this strong way to stay in the league.
"In the second half, we lost more control and the opponent had many chances with long balls. It's very hard to defend difficult long balls.
"In the end, I am very happy with the performance and with the mentality to win games. This is the biggest change with what we do in the last two months.
"When we win, other clubs drop down, but my focus is only on my team.
"I think we have big support from our fans and I am happy that we have three points. When our fans go home today, I think they say: 'Barnsley is a fighting team. This is a team with hard workers'.
"I am very, very happy. We have a team that is always fighting."
Barnsley scored in the 14th minute when Jacob Brown's low cross from the right-hand side of the area was tapped in by the unmarked Mowatt from close range.
The hosts increased their lead in the 65th minute with Brown again the provider from the right, squaring to Chaplin who fired into the net.
O'Brien pulled a goal back for Huddersfield a minute later with a thumping drive from the edge of the area.
Substitute Steve Mounie went close to equalising soon after with a shot on the turn which was touched wide by Sami Radlinger.
Fraizer Campbell wasted a great chance for Huddersfield, shooting over from a good position after meeting Juninho Bacuna's free-kick.
Mounie also fired wide with an effort from just inside the area while O'Brien had a shot blocked following a corner deep into stoppage time.
Huddersfield manager Danny Cowley said: "It's a disappointing outcome, for sure.
"I thought we started the game quite well and then conceded with their first venture into our box.
"I was disappointed with how we responded to that goal. I didn't think we got to our levels for the rest of the first half.
"I didn't think that we played with the intensity or the energy that we would have liked after the first goal.
"We came out in the second half and played with renewed intensity and more purpose. We found ourselves 2-0 down and did well to get back into it.
"We had some moments towards the end but if we're brutally honest we lacked that quality to be able to get back into the game.
"You have to play for 90 minutes. It's a tough loss and I felt for the supporters because you feel like you've let them down."