Tomas Soucek and Jarrod Bowen struck the goals for the visitors.
Lopetegui said, "It feels good to win and we're happy to achieve these three points.
"This stadium is always difficult to win in against a very good team. They have good players, a good coach and good ideas and fortunately we were able to overcome these difficulties.
"We had to defend well to give us the platform to win.
"We had to be together to overcome the bad moments. We did and were resilient to compete. We have to highlight this from the players in my opinion, that they are all together and this is one achievement from all of them, the team. The players on the pitch and the players on the bench, the players who didn't play, all of them are main actors.
"We worked so hard for the result.
"They had two clear chances in the first half, after they regained the ball in a very similar situation, and we tried to avoid that in the second half.
"We had two or three situations, clear, to score in the first half too, so in my opinion it was a balanced first half and in the second we were able to overcome the difficulties.
"Always it's a good moment to be able to celebrate with the fans.
"We worked for this win and the feeling is our energy, our petrol. This is why we are happy for the fans - we were unhappy that we were not able to offer them a victory in our last match, and the only thing we can do after is to work.
"Despite losing, sometimes you have to keep a lot of things, and sometimes despite winning you have to improve other things. This is our work."