The Norwegian described his team's performance as "fantastic" and said that the display suggests that his team has started taking his ideas on board.
"I'm very happy, especially with the first half," he told BBC Sport. "The boys were fantastic in the first 45 minutes, they just went out there and owned the game."
Deila added: "I believe in myself and the ideas I have and I know it's going to work. We have to get everyone going in the right direction and it's getting better and better with every game we play, this game is a step forward."
The result moves Celtic up to fifth place in the table, with a game in hand on the teams above them.