Ten-man Celtic lost a two-goal half-time lead but held on for what could be a precious Europa League point in Bologna.
Reo Hatate opened the scoring early on before collecting two yellow cards in three minutes.
Auston Trusty doubled Celtic’s lead but Martin O’Neill’s side came under sustained pressure after the interval and goals from Thijs Dallinga and Jonathan Rowe brought Bologna level.
Although the Italian side managed 37 attempts at goal in total, both teams had chances to win it before the game finished 2-2.
The Celtic fans celebrated the result, which puts their team on eight points ahead of their final game against the already eliminated Utrecht at Parkhead next week. A win should see Celtic qualify for the playoff round.
Former Aberdeen and Hamilton midfielder Lewis Ferguson came back into the Bologna team to captain the side but was left looking for a first career win over Celtic after his 17th attempt.
Hatate opened the scoring in the sixth minute after a gift from Bologna goalkeeper Lukasz Skorupski, who passed the ball straight to centre-forward Daizen Maeda. The Japan forward squared the ball for his compatriot to roll into an empty net.
Skorupski partially redeemed himself moments later as he clawed Yang Hyun-jun’s shot over the bar after Hatate’s pass threatened to get Maeda in behind. Liam Scales almost scrambled home the resulting corner.
The game quickly turned though as Kasper Schmeichel made his first save, from Nadir Zortea, when Celtic were briefly down to 10 men as Maeda sorted trouble with a contact lens.
The hosts kept up the pressure. Callum McGregor produced a goal-saving challenge following slack play from Hatate and Trusty delivered a series of blocks and interventions in the penalty box.
Schmeichel tipped over a corner that threatened to sail straight in and saved well from Juan Miranda’s first-time strike.
Hatate was booked for a foul on Ferguson before needlessly flicking out a boot to catch Miranda in the 34th minute as the pair chased a ball that was heading into the Bologna half. A red card followed and O’Neill also received a yellow card for his protests.
The Celtic fans were celebrating again five minutes before the break as Trusty netted in off the bar at the back post after Arne Engels had headed on Kieran Tierney’s inswinging corner.
Schmeichel saved Tommaso Pobega’s header and although Maeda swept a half-chance wide, the second half quickly developed into an onslaught of the Dane’s goal.
Schmeichel saved Ferguson’s header and Nicolo Casale’s volley before Benjamin Dominguez shot off the top of the bar.
The pressure paid off in the 58th minute when Dallinga got in front of Colby Donovan to nod home from six yards after Jens Odgaard had headed on a cross.
Maeda was now playing as a supplementary wing-back as Celtic defended but the pressure was relentless. The equaliser came in the 72nd minute as former Norwich winger Rowe made space on the edge of the box and evaded substitute Benjamin Nygren to smash a shot into the roof of the net past a motionless Schmeichel.
Celtic emerged from their shell and had opportunities to snatch an unlikely win. Substitute Johnny Kenny forced a save and might have been able to play Maeda in on a counter-attack while Liam Scales had a looping header tipped over.
There were chances for the hosts too and Schmeichel saved from Riccardo Orsolini and Nicolo Cambiaghi.
