Celtic missed the chance to grab their first victory in the Europa League after squandering a two-goal lead against Fenerbahce.
Leigh Griffiths broke the deadlock before Kris Commons fired in a superb second as Celtic looked in control.
However, calamitous defending from Efe Ambrose allowed Fernandao to halve the deficit before the striker restored parity, powering a header beyond Craig Gordon.
It leaves Celtic’s with two points from their opening two games and this game highlighted their vulnerability at the back and attacking potency in equal measure.
There was an European debut for Celtic full-back Kieran Tierney, while Robin van Persie started for the visitors despite a reported bust-up with coach Vitor Pereira.
Celtic started in the ascendancy as James Forrest found space before dragging his shot wide of goal.
Stoppages disrupted the flow of the game but Celtic soon found their stride and opened the scoring through Griffiths.
Commons corner was flicked on by Mikael Lustig in to Griffiths and the striker fired home at the second attempt though appeared a shade offside.
Celtic, galvanised by that strike, doubled their lead minutes later with a wonderful effort from Commons.
Forrest skipped past a couple of challenges before sliding the ball into the midfielder, who powered a shot into the top corner to send the Celtic support into raptures.
The hosts looked relatively comfortable but they inexplicably created their own downfall and allowed their Turkish opponents back in the game.
Questions over Ambrose’s reliability have been raised repeatedly and again he was caught out here.
The Nigerian’s header back to his goalkeeper was short and Fernandao, who had only come on as a substitute, slipped the ball underneath Craig Gordon and into the back of the net.
It was a blow to lose the goal before half-time for the Hoops but their lead was wiped out shortly into the second half as Fernandao bulleted home a header from a Nani corner as Celtic’s vulnerable zonal marking system was exposed once more.
The Fenerbahce attack were relentless and they created further chances as they looked for a third. A hopeful ball over the top found Fernandao who attempted to chip the onrushing Gordon but it went wide.
Hasan Ali and substitute Diego then forced the Celtic goalkeeper into decent saves with long-range strikes either side of Van Persie’s looping header.
But the pendulum soon swung the way of Celtic.
The impressive Forrest re-ignited their hopes of a third goal of their own, forcing Fabiano, who had been a second-half spectator, into a save; before Commons spun and fizzed a 30-yard drive which had Fabiano worried.
There was more concern for Fabiano when he spilled a straightforward shot from Lustig but his defenders bailed him out. Lustig then set up Commons but this time the midfielder fired over.