Celtic's Champions League hopes are hanging by a thread after a dispiriting 4-1 defeat by Legia Warsaw in the third qualifying round first leg at the Pepsi Arena in which the Scottish champions were lucky to escape without further punishment.
Callum McGregor got the Hoops off to a great start when he drifted in off the right flank before firing in a left-footed drive from 20 yards which gave home keeper Dusan Kuciak no chance.
However, barely had the cheers of the 160 or so Celtic fans inside the 31,000-capacity stadium subsided when Legia drew level as the Parkhead defence dropped their guard.
When Legia's highly coveted midfielder Michal Zyro played in Miroslav Radovic, the Croat had plenty of time to find the net.
The slackness prevalent in the Hoops defence would have been giving new boss Ronny Deila palpitations and in the 36th minute, just after Teemu Pukki had missed a decent chance, the home side forged ahead all too easily.
Zyro's cross was headed down at the back post by Michal Kucharczyk and Radovic fired in from close range.
When Efe Ambrose was sent packing in the 44th minute for bringing down Kucharczyk just outside the box – the free-kick came to nothing – it looked an uphill task for the Hoops in the second half.
Striker Pukki made way for midfielder Beram Kayal and Kris Commons moved up to lead the line, with captain Charlie Mulgrew dropping into defence.
There was no Legia onslaught but in the 54th minute Fraser Forster had to come to the rescue with a point-blank save from Zyro, who had been brilliantly set up by Radovic after getting the break of the ball inside the box.
Celtic were given a break when, following Mulgrew's foul on Ondrej Duda, Vrdoljak sent his penalty wide of the target and slowly the Parkhead side began to sense that they could sneak another goal, although they continued to live dangerously at the back.
Commons had the ball in the Legia net but the offside flag had been up for an age. It was further evidence, though, that the visitors did not want to settle for the narrow defeat.
Emilio Izaguirre had replaced debutant Jo Inge Berget and Leigh Griffiths came on for Commons but with six minutes remaining, Zyro headed in a cross from Radovic.
Forster 's penalty save from Vrdoljak – after another Mulgrew foul, this time in Jakub Kosecki – was then negated when Kosecki made it 4-1 in the last minute of normal time to leave Celtic with it all to do next week.