Brendan Rodgers claimed Celtic "looked like a proper team" in their narrow 2-1 Champions League defeat by Bayern Munich at Parkhead.
A moment of hesitancy in the 22nd minute by defender Dedryck Boyata allowed French star Kingsley Coman to open the scoring and blight an encouraging first-half performance by Rodgers' side.
Celtic roared back after the break and Callum McGregor deservedly levelled in the 74th minute only for midfielder Javi Martinez to restore the German giants' lead three minutes later meaning that with two Group B fixtures remaining, the Scottish champions have only three points from 12 and can not get into the knockout stages.
Rodgers, though, was pleased with his side's efforts.
He said: "The disappointment in the changing room afterwards lends us to think of how we played and our performance level.
"The level of composure and quality we played with tonight meant I was very proud of the team and we caused them lots of problems.
"Individually they are world class and you can see that at times.
"We are disappointed with the goals. We conceded two goals that you get punished for at this level.
"But overall we looked like a proper team and one that is developing at the level.
"We are disappointed to have lost but there are so many positives from the game.
"I am pleased with the way we worked the ball and it is another step for us to being a competitive side but playing proper football at this level."
Rodgers had no doubt that Boyata was to blame for the opening goal.
The Belgium defender hesitated and let a long punt from Bayern keeper Sven Ulreich go over his head.
Coman was on to the ball in a flash and rounded keeper Craig Gordon, who had rushed outside his box, before slipping the ball past the backtracking Boyata, Bitton and Mikael Lustig, with the Hoops claiming the Bayern attacker had used an arm to control the ball.
The Northern Irishman was not sure if there had been an infringement and was more concerned by how easily his defence was breached.
He said: "We have got to deal with it, as simple as that.
"We put good pressure on their keeper and our defensive line is good.
"So we have to head it.
"Craig was in a good start position. That at least gives him a chance.
"When their keeper kicks it, you want your goalkeeper high, your defence is in a good line, so head it."
Speaking through an interpreter, Bayern boss Jupp Heynckes swerved a question about possibly getting a break at their opening goal.
He said: "Celtic played an amazing game.
"The fans were a super support and it was a wonderful experience for us here."