Royal Antwerp stunned Barcelona for their first ever Champions League win featuring two goals in stoppage time.
Teenager Arthur Vermeeren put Antwerp ahead after just 90 seconds, before Barcelona equalised before half-time through Ferran Torres.
Antwerp led again via Vincent Janssen, only for Marc Guiu, 17, to seemingly grab a point in the 91st minute.
But from the kick-off Antwerp surged downfield and won the game through another teenager, George Ilenikhena.
Antwerp had lost all five of their previous Group H matches on their Champions League debut and had already been eliminated from European competition.
But the Belgian champions, who qualified for the Champions League after winning their first domestic title since 1957, fought to victory to ensure no side in the 2023-24 group stage ends with zero points.
They gave their supporters something to shout about against a Barca side, whose manager Xavi rested several first team players with top spot in the group and progression to the knockout stages secured.
Barcelona will be joined in the round of 16 by Porto, who held off Shakhtar Donetsk for second spot in Group H with a thrilling 5-3 victory in Portugal.