The visitors took the lead early in the second half but the Reds came from behind to triumph 2-1, make it three straight wins and move up to third in the table.
Stendel said: “It was not our best game but an important win and the three points were the most important thing. The mentality was good but we missed a bit of concentration. We did well to turn the game around. It is normal that we take the lead and win but we have not won many games when we go behind, so it is an important experience.
“It was a fight, even until the last seconds when they nearly scored from a corner. But we were very happy after the final whistle. Sometimes we need dirty victories and this was one of them.
“We want to be in the top two after 46 games and it is an important win to get us there. I am happy with where we are but we have 18 games to get higher in the table.”
Strikers Kieffer Moore and Cauley Woodrow got the goals. Stendel said: “Our strikers did not have their best day but in the end they scored and we won. They have the quality that we need, especially when we don’t have a good day.
“I am happy they scored but I expected a better performance. It is not too easy to show your best performance every week.” Match-winner Woodrow said: “Their goal woke us up but thankfully Kieffer scored soon after then we played a lot better. I am delighted to get my ninth goal of the season. I don’t think I had a good game but I was waiting for my chance to come and thankfully it did and I took it well so I’m pleased.
“I don’t think we performed at our best at all, individually and as a team. We were nowhere near the level we can be at but it was important we got the win in the end and we’re delighted to come out with the three points.
“Every team has their off-days and today was one of ours. We can look back and see what we did wrong. Earlier in the season we might not have won a game like that. The team spirit is really good at the moment and that helps in times when we’re not doing so well on the pitch. Everyone sticks together, keeps grinding and the chances fall to us.”
Stendel brought off winger Mamadou Thiam at half-time for central midfielder Kenny Dougall as he changed to 4-3-3 to 4-4-2. The head coach said: “In the first half we did not have the control in centre mid.
“We thought about dropping Cauley back into midfield but I thought it was better to bring on Kenny. We needed a player to come off and in this case it was Mama but it was not a decision against him.”
Keith Hill, the former Barnsley manager now in charge of Rochdale, said: “We took one of the best sides in the league all the way and they had to work hard for the victory. I love the way Barnsley play, the centre halves are happy to take the ball out of defence and they are a very good team.
“We took the lead but Kieffer Moore came up with a great finish then they got the winner. Barnsley will do that on a regular basis because they are a good side.”