Caiuby's superb stoppage-time volley secured a 2-1 Bundesliga win for in-form Augsburg over Schalke on Sunday.
The visitors missed the chance to go fourth despite Sead Kolasinac scoring his first goal for the club at the WWK Arena, where Hong Jong-ho had put Augsburg ahead.
A Schalke win would have sent them fourth, but it was Markus Weinzierl's hosts who grabbed all three points at the death to move up to 13th.
Hong's opener came via a fortuitous deflection off Philipp Max's shot 11 minutes before the break.
It looked as though the spoils would be shared when Kolasinac collected a cross from Eric Maxim Choupo-Moting and stabbed home from six yards.
But Caiuby ensured a return of 10 points from the last 12 available for Augsburg as his stunning strike settled matters in the first minute of injury time.
