Kadyrov named Muslim Khuchiyev, formerly the president's first deputy chief of staff, to replace Temirbayev.
Kadyrov, who is leading a campaign to rebuild Chechnya's war-ravaged capital, explained the move by saying that Grozny "needs new ideas and approaches."
His critics have accused him of centralizing power, creating a cult of personality, and violating human rights.
Ever since his father, pro-Kremlin Chechen President Akhmed-Hadji Kadyrov was killed in a May 2004 bomb blast in Grozny, Ramzan Kadyrov has risen to prominence.
In March 2006, First Deputy Prime Minister Kadyrov, who heads a personal army of 10,000 heavily armed fighters, was named prime minister. His reign as premier has been characterized by divisions in the Chechen leadership and accusations of torture. But he has also been credited with improving living standards in the republic.
In October, he turned 30, clearing the way for running for president.