Recently, the field of instructed pragmatics has seen a shift of paradigm from the prevailing cognitive approaches to socially-oriented ones, revolving around the notions like collaborative dialogue and sociocultural theory. Drawing on the notion of collaborative dialogue, this study investigates the extent to which teacher's scaffolding and peers' collaborative dialogue assist EFL learners' to produce requests, apologies, and refusals. It also explores the effect of symmetrical and asymmetrical proficiency pairings during the participants' collaborative dialogue on the production of speech acts. To this end, three intermediate-level intact classes were randomly assigned to the teacher's scaffolding (TS), peers' collaborative dialogue (PCD), and control groups. The PCD group was also divided into symmetrical and asymmetrical pairs based on their pragmatic pretest scores. The treatment lasted for 11 sessions. Each session involved the metapragmatic instruction followed by pragmatic problem-solving tasks, with the TS group getting the teacher's scaffolding and the PCD group collaborating in pairs while doing the tasks. The ANOVA and independent samples t-test results of the post-test scores revealed the superiority of the PCD group over the TS group. Asymmetrical pairs were also found to outperform their symmetrical counterparts. The findings reveal the potentiality of peer mediators in L2 pragmatic acquisition and point to interlanguage pragmatic gains associated with an asymmetrical proficiency pairing.