Manuel Pellegrini's men scored four goals in both halves at My Dinh Stadium as they bounced back from defeat to Real Madrid with a victory in Hanoi.
Raheem Sterling continued his fine start to his Manchester City career with a brace in their comprehensive 8-1 friendly win over Vietnam on Monday.
After opening his City account in his first appearance against Roma, Sterling went one better in Hanoi as he scored twice in 12 minutes against a national team ranked joint 143rd in the world.
The former Liverpool forward was not the only City player to find the back of the net twice in the Vietnamese capital, with Aleksandar Kolarov and David Silva also replicating the feat.