The home side were far from their best in the first leg of the third round qualifier against the Azerbaijan champions who looked a neat and tidy outfit.
It looked as if Qarabag would get away with a goalless draw until the 82nd minute when former Manchester City defender Boyata, recruited in the summer, headed in a corner from substitute Kris Commons.
Looking ahead to the return in Baku next Wednesday, Deila pointed out his team’s defensive strengths and the belief he has in them to make their way into the play-off.
Deila said: “It is hard to say if 1-0 will be enough. The game is not won yet. It was an even game. We had more chances than them, if they had one.
“I am very happy that we didn’t concede anything, we met a very good team who are hard to play against so of course it makes it easier. It is vital. We are in a good position. If we score then they need three and that is a positive. First of all we need a team over there. I think player for player we are a stronger team.
“I believe in my players. I think we are individually good and have strong qualities. We have speed in the team and hard working players in midfield and strong in defence. The two central defenders are class.
“They are also a good team, they have had the same coach for seven years working in the same system. They are relaxed and concentrated so we need to put together a very good team performance if we are going to get through. We have a good chance with 1-0.”
Qarabag boss Gurban Gurbanov said: “We knew we were going to play against a good team and that it would be difficult here and 1-0 is good for Celtic.
“It was exciting to play here in front of so many supporters but it will be interesting in the return game in front of so many of our fans. We have great supporters, like Celtic, and of course they are going to help us.”