The Italians trailed early on through an unexpected rocket from Alexander Scholz, but Amad Diallo’s arrival in the second half breathed belief into the hosts, who eventually drew level through Cristian Romero.
Atalanta had started brightly before falling behind. Papu Gomez was trying to dictate the tempo, Luis Muriel looked lively, Hans Hateboer had an effort stopped and Duvan Zapata fired an effort over before rolling one into Jesper Hansen’s arms, but they soon paid for their lack of ruthlessness.
Midtjylland were awarded a freekick in the centre of the park, much to Gian Piero Gasperini’s frustration as he wanted one of his own for what he considered a push on Muriel. A long ball forward was chested down nicely by Sory Kaba for Alexander Scholz to rifle a volley past Marco Sportiello, who barely had time to react before it travelled 20 yards into the back of his net.
Gasperini’s side went on to dominate possession, as they would have expected to, but lacked their usual zip and fluidity in the final third with Zapata, in particular, being some way short of his best form.
Changes were made as the game wore on, but nothing sparked life into a sloppy and slow La Dea performance, at least until Amad Diallo’s introduction.
Amad was put through shortly after coming on for his Champions League debut, but the teenager’s effort was parried and Zapata sent his follow-up shot over the crossbar.
Then came the leveller through an unlikely source. Hans Hateboer claimed his second Champions League assist in a week as he picked out Cristian Romero, who nodded in his first-ever European goal with a little over ten minutes to play.