Celtic manager Brendan Rodgers call his side's second-half display "absolutely sensational" after they thumped Slovan Bratislava 5-1 in their opening Champions League fixture.
Rodgers sensed a greater belief about his side as they built on their recent domestic form to record a bigger victory than they ever managed in the old group phase.
A Liam Scales header had Celtic ahead at half-time but they should have been out of sight and they added a clinical edge after the break after Rodgers called for his side to take less touches and keep a better structure in the final third.
Goals from Kyogo Furuhashi, Arne Engels, Daizen Maeda and Adam Idah gave Celtic back-to-back wins in the competition after they ended a 10-year wait for a home win with victory over Feyenoord in a dead rubber 12 months ago.
Rodgers said: "In the second half the players were absolutely sensational. The mentality, hunger, greedy for goals, greedy for the ball – working right to the very end, and we could have had more than five.
"There was a big expectation going into the game but it was important not to complicate things, just play our football and see if we could put them under stress and see if they could live with it.
"The intensity right from the off was superb and in the second half we turned the screw. We had other chances and that's what we want, we want to be really, really difficult to play against with and without the ball."
After making Parkhead one of the most feared grounds in European football in the early part of the century, Celtic have struggled at this level for a long time, and Rodgers felt the need to change the mindset.
"We want to change that mood and feeling and we have worked hard from the start of pre-season to get to this point where we can have that belief," he said.
"I said 'don't overthink it', that's the key. The razzmatazz around the Champions League is amazing but we are playing against a team who defend 4-4-2, which we play against in the league. There are different tiers but it's still the same idea.
"You can see the confidence we have from pre-season. That's the level and we want to keep showing that.
"It's giving he players the belief to play our game because those goals, you will have seen them a number of times.
"Sometimes when you are paying in the Champions League, people think you have to do something different. You don't, just get the intensity in the game, make it really difficult to play against with our pressure and fight for the ball and that will activate you with the ball.
"We know where we want to get to as a club and that was a nice step."
Slovan head coach Vladimir Weiss said: "Celtic have been very effective. I think we made a good impression even though the score says different.
"They pressed us very well, you could see their attacking players sprinting forward.
"We played to our standards. We knew we were going to face some of the best teams in the world. Credit to Celtic and Brendan Rodgers, he is a fantastic coach.
"The atmosphere in their stadium is one of the best in the world. In this atmosphere it's almost impossible."
