This paper seeks to account for the argument-function mismatches observed in Mandarin resultative compound verbs. The account is formulated within a revised Lexical Mapping Theory which incorporates a unified mapping principle. Under the simplest and also the strictest interpretation of this mapping principle (or the θ-criterion), a composite role, formed by two composing roles, receives syntactic assignment via one composing role only; the second composing role is thus suppressed. Argument-function mismatches are due to the competition between composing roles for syntactic assignment. This LMT account also facilitates a natural explanation of markedness among the competing syntactic structures.