Europa League: Efe Ambrose blunder leaves Celtic boss Ronny Deila in a spin
Celtic 2-2 Fenerbahce
Celtic manager Ronny Deila blamed "a stupid mistake" which gave Fenerbahce a way back into the Europa League Group A game at Celtic Park.
Leigh Griffiths and Kris Commons had given the home side a 2-0 lead but a blunder by Efe Ambrose let in Fernandao to pull a goal back before half-time.
When the Brazilian striker scored a second after the break Fenerbahce were level and despite their best efforts Celtic could not find a winner.
Deila said: "We started a little bit nervous. After 10 or 15 minutes we were more comfortable on the ball. We created two very nice goals.
"I think we had good control over them but of course we made a stupid mistake which happens in football, but you get punished when you are in Europe.
"We started the second half poorly and they get 2-2 from a set-play so that's also something we need to sort out, to get better. But I think we finished the game better."
Commons feels Celtic can have success in the competition if they cut out the mistakes.
He added: "I think either side of half-time was obviously pivotal for us.
"I think the turning point was both sides of the half, we conceded really late and really early. If we just sharpen up those sides of things I think we will do really well in this competition.
"It would have been nice to come in at half-time with a 2-0 lead but accidents happen. In the grand scheme of things it was probably a draw in the end."
There was talk about a rift between Fenerbahce's summer signing Robin van Persie and coach Vitor Pereira in the build-up to the game but the 32-year-old Dutchman was handed a start, supported from wide by former Manchester United team-mate Nani.
Ambrose, though, endured a personal nightmare.
A horror mistake by the Nigeria defender two minutes from the break allowed substitute Fernandao to pull a goal back.
The Brazilian striker, on in the 40th minute for the injured Volkan Sen, headed in his second goal three minutes into the second half as Deila's home side appeared still to be shell-shocked.
The visitors took control but the Parkhead side eventually composed themselves and deserved to finish with a point - it takes them to two points after two games - but will hope Ambrose's error will not prove crucial by the time the group is completed.
It was a big night for 18-year-old left-back Kieran Tierney who replaced the suspended Emilio Izaguirre to make his first European start, while midfielder Stefan Johansen came in for Tom Rogic.
James Forrest looked in the mood as Celtic drove forward with purpose in the early stages and two goals in quick succession had the Istanbul outfit rattled.
A Commons corner from the right in the 28th minute was helped on by the head of Mikael Lustig and although Fenerbahce goalkeeper Fabiano blocked Griffiths' first shot from three yards, the Scotland striker fired the rebound high into the net.
Parkhead erupted for the second time in the 32nd minute when Commons' left-footed drive from 10 yards out, after taking a Forrest cut-back, gave Fabiano no chance.
The visitors looked bereft of belief but a remarkable Ambrose mistake in the 43rd minute gave them hope.
Fernandao could not believe his luck when the defender was hopelessly short with a back-header, allowing the big striker to knock the ball past Hoops goalkeeper Craig Gordon.
Fenerbahce replaced Ozan Tufan with Brazilian midfielder Diego for the start of the second half and within three minutes they were level when Fernandao bulleted in a Nani corner with his head.
The Hoops - who drew 2-2 away to Ajax last month - looked as if they would unravel but secured what may prove a valuable point ahead of the trip to Norway in three weeks to face Molde.
CELTIC: Gordon, Lustig, Boyata, Ambrose, Tierney (Blackett 82), Brown, Bitton, Commons, Johansen (Rogic 82), Forrest, Griffiths.
Goals: Griffiths 28, Commons 32
Subs not used: Ciftci, Armstrong, Mackay-Steven, Bailly, McGregor.
FENERBAHCE: Fabiano, Ozbayrakli, Kjaer, Bruno Alves, Ali Kaldirim, Tufan (Diego 45), Topal, Meireles (Ba 79), Sen (Fernandao 40), Van Persie, Nani.
Goals: Fernandao 43, 48.
Subs not used: Demirel, Zeybek, Potuk, Erkin.
Man of the match: Fernandao
Match rating: 7/10
Referee: Kenn Hansen (Denmark)