Uniao remain winless since the opening day of the Primeira Liga season, having fallen to a 1-0 defeat against Belenenses this evening.
Both sides registered plenty of shots on goal at the Estadio do Restelo, but it took until the dying stages to find a way through.
Tiago Caeiro was the man to register the only goal, as he broke the deadlock in added time to earn O Belem all three points.
Belenenses, who came into this game on the back of an impressive away win over Basel last week, are now up to 10th place thanks to their second league victory of the term.
Uniao, on the other hand, who could not find a way through with their three shots on target, remain two points above the drop zone.
