Gian Piero Gasperini’s side only needed a point to progress, but they never looked as though they were only playing to shut the Dutch side down, successfully putting their poor recent form behind them to claim another memorable result.
The evening’s action started quite brightly, with both sides looking to get at one another and strike first, but things then grew a little more cagey as the importance of the occasion dawned on the players.
Marten de Roon had Atalanta’s best chance of the opening 45 minutes, and Atalanta would have been left wishing the ball had broken to any of their other midfielders or forwards as the Dutchman sliced a shot wide from the edge of the area.
Brian Brobbey had the hosts’ best chance, but his headed effort was too central and easily clutched by Pierluigi Gollini.
Duvan Zapata had been playing well up top and that continued in the second half with La Dea increasing pressure on Ajax, which prompted Nicolas Tagliafico to be withdrawn in an attacking change, with Klaas-Jan Huntelaar on in his place.
Davy Klassen had the game’s biggest chance. Clear on goal, he drove a low shot that Gollini did well to turn away from danger.
Luis Muriel replaced compatriot Zapata late on and he had a big chance having been found by Papu Gomez, but got under the ball and headed harmlessly over.
It was the No.9 who got the decisive goal as the 90th minute approached after Ajax had been reduced to ten men with Ryan Gravenberch sent off for a second yellow card. Remo Freuler won the ball back high up the pitch and slipped a perfect ball into the striker’s path, allowing him to round Andre Onana and slot into an open goal.