Returning to Guria, his rule was challenged by a faction of local nobility, which included his mother Elene and brother Kaikhosro III Gurieli.
When Mamia seized the throne of Imereti in October 1712, Giorgi was made by his father as regent of Guria to the opposition of his younger brother, Levan.
His reign lasted for only three months; the dethroned king Giorgi VII's Rachian supporters ambushed and looted Gurieli's treasure, bound to Kutaisi, at Salominao, while a Gurian escort were captured and sold in slavery.
Gurieli moved to Erzurum and, with the troops provided by the local pasha, quickly reconquered Guria, forcing his mother and brothers into exile.
He then moved against his estranged nobles, expelled Eristavi, and took away Giorgi Nakashidze's wife, a daughter of Dadiani, as his own mate with her father's consent.