This paper investigates the interface between syntax and information structure in sentences involving middle-field topicalization in Brazilian Portuguese. In particular, it aims at determining the syntactic conditions governing the proper relative positioning of contrastive topics and their associated foci, a relation I call Contrastive Topic-Focus Association (CTFA). Dispensing with topic- and focus-dedicated cartographic projections in the middle field of BP, I argue that the constraints on CTFA (in particular, the requirement that a middle-field topic and its associated focus be in the same Spell-Out Domain) are better accounted for by a configurational approach to the mapping from syntax to information structure (as in Neeleman and van de Koot 2008, 2010 and unlike, e.g., Rizzi 1997, Belletti 2004).