Aleksandar Mitrovic consigned Cristiano Ronaldo and his Portugal teammates to a World Cup play-off spot, whilst securing qualification for Serbia, thanks to a dramatic late winner.
Serbia clinched a 2-1 victory, despite Portugal needing only a draw to qualify for the 2022 World Cup in Qatar.
Renato Sanches opened the scoring for the hosts inside just two minutes after Bernardo Silva regained possession and found the Lille midfielder to finish.
Yet the visitors were not to be deterred and found an equaliser just after the half four mark when Dusan Tadic somehow beat Rui Patricio to sneak a shot over the line.
Ronaldo has developed a penchant throughout his decorated career of scoring late goals, yet he barely tested Predrag Rajković.
Instead, Mitrovic stole the headlines as he powered home a header whilst unmarked at the back post to send the visitors into a state of delirium as the bench emptied and the Fulham striker whipped his shirt off.
Serbia finish top of Group A with 20 points, three more than Portugal, whose hopes of playing in Qatar next year rest on two rounds of play-offs in March.
The Republic of Ireland finished in third spot with nine points, the same as Luxembourg, after defeating the minnows away from home on the same night.