After Armenia lost its independence to the Bolsheviks, Yerganian went to Tbilisi where he and Misak Grigorian were assigned to assassinate former Prime Minister of the Democratic Republic of Azerbaijan Fatali Khan Khoyski and leader of the Musavat party Khan Mahmadov.[2] On June 19, 1920 they met at Tbilisi's Yerevan Square as they awaited a signal from their accomplices. When Khoiski and Mahmadov were 100 to 150 meters away, they immediately opened fire on them. Khoiski was killed instantly, but Mahmadov, who was only wounded, escaped.[2]