A second-string AC Milan side clinched top spot in Europa League Group H after a first-half goal from Norwegian forward Jens Petter Hauge gave them a 1-0 win at 10-man Sparta Prague on Thursday.
Milan finished on 13 points from six games, two more than Lille who lost 3-2 at Celtic but had also clinched a place in the second-tier competition's last 32 alongside the Italian seven-times European champions.
Sparta finished third on six points and Celtic were left rooted to the bottom of the standings despite winning their first match of the campaign.
Hauge netted the winner after a fine solo run in the 23rd minute, beating two defenders with neat footwork before he steered the ball into the far corner with a crisp low shot.
Sparta keeper Milan Heca denied Diogo Dalot and Samu Castillejo either side of Hauge's strike before the game fizzled out in the second half.
The Czech side had central defender Dominik Plechaty sent off in the 77th minute for a foul on Rafael Leao.