Barcelona fell to their first defeat of preseason on Wednesday as Brenden Aaronson's late goal saw them beaten 2-1 by Red Bull Salzburg.
The Austrian side were the better team at the Red Bull Arena and took the lead through Luka Sucic just before the break.
Substitute Martin Braithwaite looked to have saved a draw for Barça with a fortunate late goal before Aaronson's 90th-minute winner.
Ronald Koeman switched from 4-3-3 to 3-5-2 for the first time in preseason as Barca looked to make it four wins from four.
However, Salzburg dominated large parts of the game and could have been two or three goals ahead by the break.
Noah Okafor in particular was guilty of missing two great chances before Sucic's effort deflected off Frenkie de Jong and beyond Neto.
Salzburg were less dominant after the break and Barca finally came into the game in the final 15 minutes.
Alejandro Balde and Memphis Depay both tested the goalkeeper from distance before Braithwaite inadvertently drew Barca level.
Sergiño Dest's shot ricocheted off a defender and off Braithwaite into the back of the net in his first appearance of preseason.
But the home side stepped up in the final five minutes and Aaronson was the quickest react to roll home after Chukwubuike Adamu hit the post.