How does control over legislative procedure shape the behavior of Members of Parliament (MPs) in emerging democracies? This paper explores a rare institutional shift in Ghana's Fourth Republic, where, for the first time in 2021, an opposition party member was elected Speaker of Parliament, a position typically held by the ruling party. Leveraging a difference-in-differences design with a newly created MP-Year panel data from Ghana's parliamentary Hansards from 2017 to 2024, I estimate the causal effect of opposition control over procedural leadership on MPs’ speaking behavior. The findings show that, following the institutional realignment, opposition MPs significantly increased their speech frequency and speech length, particularly in non-lawmaking and government oversight functions. These effects are absent in lawmaking speech activities. The results demonstrate how procedural leadership can amplify legislative voice and strengthen minority oversight capacity, even in the absence of formal numerical power. Robustness checks including event study, placebo tests, first difference estimations, and alternative sample constructions validate these findings. This study contributes to the literature on legislative behavior, opposition party politics, and institutional power in emerging democracies.