Tomas Soucek and Aaron Wan-Bissaka struck the goals on Monday night to ease pressure on Lopetegui.
Lopetegui later said, "We are happy. I think that we played well. We played with one identity and we were able to overcome a very good team. They started well and it is always good to have more confidence. They had two chances and I think that in the second half we did well and deserved to win.
"I am happy for the players, for the team and for the fans. They will have to drive a lot of miles so we are happy for them. We look forward to the next challenge. We are happy but we have a lot of work to do.
"We have to build as a team if we are to work and know what we want to do. I think about the play. That is the thing that we try to do. We have a lot of matches that we need to do and I believe in the future this team is going to be able to do the things and show the style as a team.
"The players believe and they are able to do do this and put in the focus every day. Each match is one incredible challenge in the Premier League."
Asked about Europe, he also said: "I don't talk about this. We only talk about the next day. Tomorrow we are looking forward to the next challenge and the next step is not to think about the long term. That helps no one.
"I think we should be but we are a good team. That is the most important thing. Our big challenge is to be able to be a good team."
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