Oliveirense's first defeat came in the 4th round

Oliveirense suffered their first defeat in the fourth round of an unspecified sporting competition in the article. The title indicates that until that stage, the team had maintained a positive or unbeaten record. The available information is limited and does not specify which competition is involved, who the opponent responsible for the defeat was, or what the score of the match was. The article refers exclusively to this moment as a milestone in Oliveirense's season, without providing additional details about the broader competitive context.