Celtic's hopes of staying in Europe were ended after AC Milan came away with a win from their Champions League encounter in Glasgow, putting the Scottish champions out of the competition.
Milan were in front after 12 minutes when Kaka headed unopposed from the edge of the six-yard box to beat Fraser Forster.
The hosts struggled to carve out a clear opportunity in the first half with arguably their best chance falling to Giorgios Samaras just before the break, but he couldn't generate enough power to trouble keeper Christian Abbiati.
Celtic's best chance to equalise fell to Virgil van Dijk when a free kick rebounded to Charlie Mulgrew who found the Dutch defender unmarked, but he could only hit his shot at the Milan stopper.
They were made to pay moments later when Valter Birsa's deep corner found Antonio Nocerino and his ball back across goal reached the unchallenged Cristian Zapata, who tapped home from close range.
Van Dijk thought he'd pulled a goal straight back when his looping header found the left corner, only for the linesman the flag for offside.
Mario Balotelli made sure of the win for the Rossonieri on the hour mark, when he held off Efe Ambrose's challenge and hit his shot across Forster inside the left post.
The defeat twinned with Ajax's surprise win at home to Barcelona means that the Hoops cannot even qualify for a place in the knockout phase of the Europa League.
