Emergentist, usage-based L2 research has witnessed that emphasizing formulaic sequences as entry points in meaning-based instructional contexts contributes to the development of linguistic comprehension and production. Related studies have thus far striven to find the most effective methods of highlighting these word strings. This study explored the effects of the focus on lexis (FonL) approach on L2 learners' development of phraseological competence. Furthermore, it probed whether incidental and intentional FonL approaches result in any differential effects on the learners' development of phraseology. Participants were 60 L2 learners in three intact classes randomly assigned to one control and two experimental FonL groups. Their general language proficiency was measured by administering a Cambridge PET Test. Additionally, a pre-test was used to measure their prior knowledge of phraseology. The control group received the mainstream typical instruction, whereas the experimental groups received incidental versus intentional FonL, differentially heightening noticing of conventionalized lexis expressions in L2 reading. A parallel posttest was administered to measure the development of learners' phraseological competence. ANCOVA results indicated that the lexis groups made greater gains in their phraseology as compared to the control group. Moreover, differential effects were evidenced specifically in favor of the use of intentional FonL. The findings indicate that the varied amount of attention L2 learners pay to aspects of formulaicity in language use can influence the extent to which lexis-based input and interaction lead to intake. Theoretical and pedagogical implications of the study are discussed at the end.