Udinese 1-1 Glasgow Celtic: Hooper, Di Natale score
Celtic made an agonising exit from Europe after holding Serie A pacesetters Udinese to a 1-1 Europa League draw in a pulsating contest at the Stadio Friuli.
With both sides committed to attack, Neil Lennon's side could easily have emerged with the win they needed in a game that raged from end to end throughout the evening.
Celtic grabbed a merited lead when Gary Hooper slipped the ball home from close range on 28 minutes only to be undone a minute into two of time added on in the first half as Cha Du Ri nodded into the path of Antonio Di Natale, who slipped the ball home from five yards out.
The visiting goalkeeper Fraser Forster made some exceptional saves in the second period, but Celtic were also left to rue their luck as Cha saw a shot come back off a post in the second half.
They were also denied a clear-cut penalty when Mehdi Benatia handled in the area from Daniel Majstorovic's header.
Di Natale showed his menace early on when he lobbed the ball over Forster and over the bar after Scott Brown had needlessly squandered possession, but Celtic looked the brighter side as they carried the game to the home side.
Danilo was fortunate to be awarded a free-kick when he clearly obstructed a rampant Georgios Samaras as he bounded towards goal before Hooper clipped a shot wide from 10 yards out after being played in by Samaras when it looked easier to net.
Celtic were rewarded for the adventure of their play when Samaras' cross broke kindly off Joel Ekstrand for Hooper to score. Celtic looked to have done enough to establish a lead at the break, but Di Natalie showed why he is top goalscorer in Serie A with 10 goals courtesy of an opportunistic finish.
As the second half caught fire in the freezing cold conditions, Forster halted Di Natale from adding to his tally by diving to claw out a thumping shot by the striker from distance before standing tall to save another Di Natale effort moments after Majstorovic had been caught out of position.
Forster then dived to deny Di Natale from netting with a header as Udinese pushed for the second goal they craved to kill off the Scottish side.
With Celtic continuing to push bodies up the park, Kwadwo Asamoah hit a post from close range to the frustration of the home fans after the inspired Forster had blocked Mauricio Isla's header with Charlie Mulgrew beaten in the air.
Celtic maintained their offensive ploy and Cha was left looking bewildered as his volley hit a post before the ball just stopped short of the line after hitting the back of the beaten home goalkeeper Samir Handanovic on 75 minutes.
The visitors had plenty of bodies in the box deep in injury time as Handanovic missed Mulgrew's corner.
But Celtic could not force the ball over the line to come up narrowly short of leaving Udine with three points that would have carried them through to the knock-out stages.
Udinese: Samir Handanovic-Dusan Basta-Danilo-Mehdi Benatia-Joel Ekstrand-Pablo Armero-Almen Abdi-Tape Doubai (Mauricio Isla 46)-Kwadwo Asamoah-Emmanuel Badu Agyemang (Giampiero Pinzi 29)- Antonio Di Natale
Celtic: Fraser Forster-Daniel Majstorovic-Du-Ri Cha-Charlie Mulgrew-Scott Brown -Baram Kayal (Anthony Stokes 71)-Ki Sung-Yueng-Victor Wanyama-Georgios Samaras (Mohamed Bangura 83)-Gary Hooper-James Forrest