Substitutes Callum Osmand and Camilo Duran inspired Celtic to their first Europa League win of the season, a chaotic comeback victory against Turkish giants Besiktas.

Junior Olaitan's goal - a rebound after Sam Johnstone saved his penalty - looked like condemning Celtic to a grim club record of five consecutive defeats in European competition.

But Martin O'Neill's side were transformed after a triple substitution just after the hour mark, when Osmand, Duran and Colby Donovan entered the fray.

Osmand and Duran scored three times between them, and Osmand also grabbed an assist in a chaotic final half hour during which Celtic came from behind to lead, and were then pegged back, before Duran won it on 87 minutes.

Just 43 seconds after Osmand entered the pitch, Callum McGregor read a pass into midfield by Besiktas and pinched possession, before feeding the 20-year-old substitute.

Osmand did the rest as he drove up to the edge of the box and drilled the ball low past Alexander Nubel to level the game.

From there, the previously flat crowd roared into life and Celtic's intensity completely changed.

Liam Scales had a header pushed over from a corner and Osmand slipped in Benjamin Nygren, who whipped a right-footed shot just over the crossbar.

But Osmand was not done there, as he then teed up Duran, who stayed calm to round Nubel and slide the ball home.

Then, came an unexpected twist. Orkun Kokcu wrestled momentum back for Besiktas with a belting strike from the edge of the box which flew past Johnstone.

However, Celtic's response was almost instant. Kieran Tierney drove forward and scuffed his shot, but it fell for Duran to side-foot home from close range and - after a check for offside - Celtic Park went berserk.

Almost cheered as loudly was Johnstone's terrific take from a Besiktas cross, which signalled the end of the game and a desperately needed Europa League win for Celtic.

As European nights at Celtic Park go, this will go down as one of the strangest. Until the triple substitution on the hour mark, nobody in the grand old stadium could see a Celtic response coming.

They had just two touches in Besiktas' box in the first half, barely laying a glove on their visitors.

And when Johnstone's poor kick out was followed by Jordan Lotomba's rash challenge on Ernest Poku and a Besiktas penalty, the writing was on the wall for a side who looked utterly bereft of confidence.

However, Osmand and Duran completely transformed the energy of the Celtic team. They inspired their team-mates - and supporters - with their energy and willingness to run with the ball and play positively.

While Kasper Hogh, now 15 games without a goal, appeared hesitant, Osmand showed incisiveness with his first touch to surge forward and lash in.

Duran, now on 13 goals for the season, also demonstrated his usual sharpness and composure amid the bedlam of a revitalised Celtic Park, which had plenty of empty seats amid ongoing fan unrest.

O'Neill has admitted he still is unsure of his best XI, but the 74-year-old will now surely have to include Osmand and Duran whenever possible.

As good as the victory feels, the substitutes' performances will not mask everything about Celtic's recent problems. But they could be the catalyst to inject some desperately needed confidence.

Celtic manager Martin O'Neill: "It's a relief we've got off the mark and got some points on the board. The game was pretty difficult but we came through it with flying colours.

"I just said to the team they were a credit to the football club, you can't get a bigger accolade than that. We could've caved in after the penalty goes in but we came roaring back and the subs made a big difference. We've got a lot of pace up front but I was just delighted with the whole team.

"I think this will boost our confidence now, we have a tough game on Sunday then the international break, but to win the European game tonight is great. The European games are tough but we came through that test and that's a big boost."