Celtic manager Ronny Deila has called for improvement, despite watching his team win on Wednesday.
The Scottish champions were 4-1 winners over Icelandic outfit Stjarnan to seal a 6-1 aggregate victory in their second-round UEFA Champions League qualifier.
Leading 2-0 prior to kick-off away frome home, Celtic surprisingly found themselves behind on the night to Olafur Karl Finsen's seventh-minute opener.
However, Celtic hit back through Nir Bitton in the 32nd minute, before Charlie Mulgrew, Leigh Griffiths and Stefan Johansen completed the scoring in the second half.
Deila was far from convinced by Celtic, who now face Azerbaijan's Qarabag in the third round of qualifying.
"We need to improve. They are a good team. I saw them play the first leg at home against the team from Montenegro and it is a big step up from what we have met here," Deila said.
"I think we were a bit sloppy at the start of the game but we got the goal and we knew things were happening.
"In the second half there was only one team on the pitch and we won quite easily.
"We didn't want to concede an early goal but it happens sometimes. We came back and 4-1 is a positive result and I am looking forward to the next round."
