Celtic's Champions League hopes are hanging by a thread after they slumped to the bottom of Group H with a 1-0 defeat by Ajax at the Amsterdam ArenA.
Lasse Schone, who had scored after coming on as a substitute in the 2-1 defeat at Celtic Park, grabbed the winner with a well-taken goal in the 51st minute to sink the Scottish champions who were far from their best in what was mostly a scrappy game.
Hoops keeper Fraser Forster strengthened his claim for an England cap with two good saves in the first-half which was bereft of quality and in which Neil Lennon's men hardly threatened.
The game opened up after the break. Schone struck just after Celtic midfielder Beram Kayal had missed a good chance for the visitors and before Anthony Stokes failed with a good opportunity to level.
Celtic, whose Dutch defender Virgil van Dijk was immense, remain on three points with two fixtures remaining.
Ajax move above them on four points with Barcelona having qualified following their 3-1 win over AC Milan at the Nou Camp.
AC Milan visit Celtic Park later this month before the Hoops travel to the Nou Camp in December to play Barcelona.
Celtic were boosted by the return of Georgios Samaras and Kris Commons who recovered from respective knee and hamstring injuries.
Skipper Scott Brown and Nir Biton missed out through suspension but Mikael Lustig shrugged off an on-going hip problem to take his place at right-back with Kayal coming into midfield.
Ajax coach Frank De Boer made three changes from the team that lost 2-1 in Glasgow to leave them bottom of the section with one point from three games.
Nicolai Boilesen, Davy Klaassen and Schone in for Lucas Andersen, Christian Poulsen and Viktor Fischer, all of whom started on the bench.
In a reshuffled line-up which smacked a little of desperation, De Boer moved Daley Blind from left-back into midfield and captain Siem de Jong from midfield into forward.
The decision to close the stadium roof had been taken during the day which meant the decibel level was raised to produce a great atmosphere.
However, some home fans momentarily held up an offensive banner aimed at the Parkhead club's Irish roots on what was its 126th anniversary and which may be looked into by UEFA.
The home side started with purpose and in the sixth minute Forster made a good save from Stefano Denswil's 25-yard free-kick, after Commons had fouled Blind, with the corner coming to nothing.
There was an Ajax claim for a penalty moments later when right-back Ricardo van Rhijn's cross struck van Dijk but German referee Deniz Aytekin was unimpressed.
In the 16th minute Forster came to the rescue again for the Glasgow side when he pushed away a downward header from de Jong, who had escaped Hoops defender Efe Ambrose to get on to the end of a van Rhijn cross.
Ajax were on top but there was enough slackness about their play and passing to encourage the visitors who, however, were not helping themselves with the amount of dangerous free-kicks they were conceding.
Four minutes into the second-half, after the Dutch side lost possession once more in attack, Kayal was allowed to run 50 yards to the edge of the Ajax penalty area but he blazed his drive high over the bar.
Celtic were made to pay for that moments later when Schone slipped the ball past Forster from 12 yards after working a one-two with Thulani Serero at the edge of the Hoops box.
With that, the game opened up further and Stokes had a chance in the 54th minute when he was set up by Commons but his low drive was dealt with by Jasper Cillesen.
At the other end, Schone's in-swinging corner from the left was headed off the line by Izaguirre with Forster beaten.
Ajax were leaving huge gaps as they went looking for number two and in the 57th minute James Forrest should have picked out Stokes as he raced down the right but managed to hit Joel Veltman, the only Ajax outfield player back.
Lennon's side had another opportunity in the 67th minute when Klassen was penalised for blocking Commons' pass 25 yards from goal but the former Derby player drove the ball straight to a grateful Cillesen.
Celtic's Dutch forward Derk Boeriggter replaced Stokes, Joe Ledley came on for Kayal and Teemu Pukki took over from Commons as Lennon tried another route.
Both sides continued to spurn good chances to create goal-scoring opportunities, with Forster making a save from de Jong with five minutes remaining before the unmarked Denswil headed the corner off the post and behind.
Celtic will go into the game against Milan probably needing a victory to have any realistic chance of progression.