Boss Brendan Rodgers stressed the need to retain possession better after Celtic let slip an early lead to lose 3-1 in Salzburg on Thursday night.
French striker Odsonne Edouard put the visitors ahead in the Europa League Group B fixture after less than two minutes.
The Austrian champions, who reached the semi-final of the tournament last season, dominated thereafter and two goals in six second half minutes from Israel international Munas Dabbur NS fellow attacker Takumi Minamino, both from cutbacks, put the home side ahead.
Parkhead winger James Forrest was then sent off in the 72nd minute for denying skipper Andreas Ulmer an obvious goal scoring opportunity and Dabbur slotted home the penalty.
Rodgers was impressed by Edouard’s goal as he brushed aside the weak challenge of defender Andre Ramalho and calmly placed his right-footed shot past keeper Alexander Walke but bemoaned his side’s inability to keep the ball.
The former Swansea City and Liverpool boss said: “It was a great start for us. Good pace to get there, pace and strength and then a wonderful finish.
“You can see how Salzburg play, they are a very good side but we limited them really in terms of clear chances.
“But at this level you have to be better with the ball and keep the ball and be able to play quicker with minimal touches, otherwise you don’t get a rest in the game and that hurt us.
“But the guys gave everything, even when down to 10 men they were running, fighting, working and as I said we were just beaten by the better team.”
While Salzburg top the table with six points from six Celtic have three points from their match day one win over Rosenborg at Parkhead.
The Scottish champions now face a double-header against RB Leipzig, starting with a trip to Germany late in the month.
Rodgers could not hid his disappointment at defensive sloppiness in the second half.
The Northern Irishman said: “I think the best team won. I thought in the first half we started well and by the end of the half we had frustrated Salzburg, you could see in their game and play and we carried a threat when we broke out of our shape.
“So the first half I was reasonably pleased with, the second half we gave away disappointing goals. That was the frustration for us and then from that they gain confidence.
“And obviously when it gets to 3-1 it is a difficult game for us with 10 men.”
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