A limp display from the hosts saw Massimiliano Allegri's side claim a comfortable victory and boost its chances of reaching the knockout stage of the Champions League.AC Milan halted a seven-game winless slump by clinically ending Celtic's Champions League campaign with a 3-0 win in Glasgow.
Celtic was backed by the cacophony of noise synonymous with its Champions League nights at home Tuesday, but slack set-piece defending decisively undermined its efforts in this must-win Group H encounter.
Kaka and Cristian Zapata were the beneficiaries either side of halftime, leaving Mario Balotelli to seal the points on a night when the enigmatic Italy international proved a thorn in the side of the home defense.
Ajax's shock win over Barcelona means Celtic is unable to even secure the consolation of a Europa League place, while Milan must avoid defeat against the Dutch champions at San Siro in two weeks to secure their passage.
Neil Lennon made four changes to his Celtic starting XI, including a decision to start James Forrest despite the winger being arrested earlier Tuesday over an alleged sexual assault. Balotelli led Milan's attack, while Valter Birsa and Riccardo Montolivo came in for Alessandro Matri and Sulley Muntari after Saturday's 1-1 draw with Genoa.
Derk Boerrigter should have put Celtic ahead in his first Champions League start for the club after just two minutes, but he scuffed a back-post volley after Milan goalkeeper Christian Abbiati made the first of a series of misjudgements from Charlie Mulgrew's corner.
A minute later, Balotelli botched a chance to open the scoring as he dragged wide having escaped the attentions of the home defense. Milan defender Zapata produced a vital last-ditch tackle when Mulgrew's ninth-minute shot fell to Beram Kayal in front of goal, and the visitors were ahead soon after.
Kaka was left completely unmarked to nod home as goalkeeper Fraser Forster elected to stay on his line on Birsa's right-wing corner.
Daniele Bonera then made a timely block after Mulgrew picked out Boerrigter, but Celtic was almost hit on the break immediately as Kaka released Balotelli to drill narrowly over. Celtic continued to press manfully before the break but its fate was sealed by two key incidents shortly after the break.
Center back Virgil van Dijk smashed a volley into Abbiati from point-black range when it might have been easier to score in the 47th minute, and his defensive colleagues were once again undone from a set piece two minutes later.
Birsa's delivery was superb again, and halftime substitute Antonio Nocerino knocked across goal for Zapata to apply the finish.
To compound Celtic's misery, Balotelli sealed the points with an hour played after Van Dijk had headed home from an offside position. The former Manchester City striker demonstrated his pace, power and poise to hold off Efe Ambrose and finish Montolivo's lofted pass.
The game the petered out as Celtic's enthusiasm faded and Massimiliano Allegri's men kept their hopes of reaching the last 16 very much alive.