Celtic's Europa League hopes were blown off course against Molde in dreadful conditions at the blustery Aker Stadion in Norway.
The artificial surface was rendered all but unplayable in places by swirling wind and rain as first-half goals by striker Ola Kamara, who had played under Hoops boss Ronny Deila at Stromsgodset, and defender Vegard Forren gave the home side a two-goal interval lead.
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As the players continued to slip and slide after the break, Kris Commons reduced the lead in the 54th minute with a well-taken goal but seconds later Mohamed Elyounoussi restored the Norwegian club's advantage.
Celtic could not get back into the match and have two points from three Group A games with Molde still sitting atop with seven points ahead of their visit to Glasgow on November 5 where Deila's side need a win to get back on track.
Deila, back in his home country, made three changes to the side which started the 1-0 win over Motherwell at Fir Park on Saturday.
Right-back Mikael Lustig replaced Tyler Blackett with Efe Ambrose moving into the centre of defence, Norway midfielder Stefan Johansen came in for Tom Rogic and top scorer Leigh Griffiths was back at the expense of Nadir Ciftci.
It was Ole Gunnar Solskjaer's first official game as boss of the home side following his return to the club for the second time on Wednesday.
But the former Manchester United striker went with the team already picked by Erling Moe, who had been in caretaker charge since Tor Ole Skullerud was sacked in August, which saw Knut Olav Rindaroy and Elyounoussi come in for Per Egil Flo and Sander Svendsen.
It was difficult for both sides to get any sort of passing game going but initially the visitors looked to be coping better.
However, in the 11th minute, with almost their first meaningful attack, Molde took the lead.
Defender Dedryck Boyata's pass was cut out by Elyounoussi and when he knocked a simple pass into Kamara who opened his body up before drilling his shot past keeper Craig Gordon at his near post.
There was more woe for the Scottish champions seven minutes later following a Molde corner which allowed the home side to pin Celtic back.
From the left, Joona Toivio crossed for fellow centre-back Forren to volley past Gordon from 14 yards, the ball first coming off the surface before speeding into the net.
Just before the break, in a swift Molde counter, Gordon did well to tip a cross from Elyounoussi over the bar for a corner, which the Hoops survived but their vulnerability at the back remained clear.
When Commons took advantage of a mistake in the Molde defence by Martin Linnes to skilfully chip the ball past Horvath soon after the break, it gave the Parkhead side a lifeline.
However, the Celtic fans were still celebrating when the Norwegian side ran up the park and established again their two-goal lead, Elyounoussi converting a cross from Mattias Mostrom at the back post with a close-range drive.
The goal stunned Deila's side and in the 62nd minute they could have lost another when Linnes picked out Kamara with a pin-point cross but the Norwegian forward misjudged the flight of the ball.
Kamara then missed a one-on-one with Gordon, skewing his shot wide of the far post.
Gary Mackay-Steven replaced Armstrong in the 73rd minute and Ciftci came on for Commons who showed his raging at the decision as he went into the dugout.
Gordon then saved from Molde midfielder Etzaz Hussain after the Hoops defence was again cut open before Hoops midfielder Nir Bitton sent a dipping shot off the top of the crossbar with two minutes remaining and Ciftci headed wide and with that close call went Celtic's hopes of a late recovery.
FENERBAHCE 1 AJAX 0
Fernandao climbed off the bench to breathe life into Fenerbahce's Europa League campaign with a late winner against Ajax.
With one point from two Group A games, the Turkish side were in need of victory but some modest finishing and a fine goalkeeping effort from Jasper Cillessen looked set to frustrate them.
That changed in the 89th minute when the Brazilian striker saw headed a corner home via a hefty deflection for his fifth goal in the competition.
The start of the game was punctuated by a series of fouls but when it finally settled down it was the hosts who made the running.
On-loan Liverpool winger Lazar Markovic was frustrated to see three shots blocked in quick succession before Diego finally worked Cillessen.
Moments later Cillessen was on hand to deny Robin van Persie with a superb piece of goalkeeping.
Ajax looked lively too but it was the hosts who fashioned better openings, Simon Kjaer diverting Caner Erkin's free-kick wide from a good position.
Van Persie finished tamely again in the 32nd minute having found space, while Nemanja Gudelj powered one of Ajax's better chances clean into the stand.
Van Persie had scored in his last two matches for club and country but his radar was off again eight minutes into the second half, while Cillessen denied another former Manchester United man, Nani, soon after.
With the home fans willing them on, Fener came desperately close in the 67th minute.
Souza saw his goalbound header cleared off the line by Lasse Schone, with Diego's cleanly-struck follow-up also bravely blocked.
Fabiano needed to be alert to stop Ajax scoring against the grain at the other end, Davy Klaassen meeting Schone's tempting cross.
When Ozan Tufan erred in the 81st minute a stalemate seemed certain, but Van Persie replacement, Fernandao, managed to find the messy winner.