Bamidele Oloyelogun, speaker of the Ondo house of assembly, and Iroju Ogundeji, his deputy, have been sacked from their positions.
The lawmakers were removed on Friday by their colleagues.
Olamide George, lawmaker from Akure north, emerged as the new speaker while Abimbola Fajolu, lawmaker from Ile Oluji/Okeigbo constituency, was elected as his deputy.
The change was effected at a rowdy plenary where Jumoke Akindele was temporarily picked as acting speaker before the emergence of the new leadership.
Following the removal of the speaker and his deputy, members of the Ondo chapter of the National Union of Road Transport Workers (NURTW) invaded the assembly and chased out the lawmakers.
The police subsequently arrived at the Ondo assembly premises to restore order.
The removed speaker, who represents Ifedore constituency, was elected in April 2017.
His election came after 13 lawmakers suspended Akindele as speaker.
Subsequently, Oloyelogun, a two-term member of the parliament, defected from the Peoples Democratic Party (PDP) to the All Progressives Congress (APC).