Moises Caicedo broke the deadlock on 78 minutes to earn the 1-0 win at Stamford Bridge.
Celades said afterwards: "First of all, I'm very proud of the players because they did an amazing defensive job. It's very difficult to come here and play against Chelsea, one of the best teams in the world. To keep them out until the 78th minute was because the players did a very good job.
"I'm still evaluating some of my players because I've only been here for ten days. So, we are trying to implement something that can help us to get better.
"Of course, the coaching staff before did an amazing job. We are working every day to keep growing. I'm very happy at the club. I think the people at the club, all the staff - I have no doubts this club will grow more."
On his approach, Celades added: "It's so difficult to play against Chelsea, in an important game at the top level, the Champions League which is the best competition in the world. And Chelsea needed to win to get into the top eight. We knew it would be difficult, but we had a plan and we were very close to taking something from here.
"We tried to take some chances on the counterattack. In the first half, we hit the post. We tried and that's why I'm proud because they did very well."