The hosts seemed in complete control after Scamacca opened the scoring in the 16th minute and Zappacosta doubled their advantage in the 53rd minute. However, Athletic Club's response was swift and decisive. Guruzeta sparked the comeback with a crucial goal in the 58th minute, injecting new life into the Basque side's challenge.
Serrano and Navarro then completed the remarkable turnaround with goals in the 70th and 74th minutes, leaving Atalanta stunned. Despite dominating possession 70% to 30% and outshooting their opponents 14-4, the Italian side could not prevent their dramatic defeat.
Scamacca's early goal and constant threat for Atalanta was ultimately overshadowed by Guruzeta's pivotal performance for Athletic Club. The visitors' clinical finishing proved the difference in this extraordinary Champions League encounter.
Atalanta will look to bounce back when they travel to Parma on January 25, while Athletic Club host Sporting CP on January 28 in Matchday 8.