During service in South Vietnam he commanded D Company 5RAR with distinction and outstanding success. His aggressive leadership, personal courage and skilful handling of his company resulted in the capture and destruction of over 2,000 enemy bunkers, the capture of large quantities of weapons and supplies and the outstanding figure of 124 enemy killed.
In January and February 1970 when Major Blake¹s company was operating at only half strength, he refused all advice to leave his troops on their final operation although in severe pain from an illness as a result of which he has since been hospitalised. For six weeks he led his small company in a most aggressive search for the enemy. His frequent successes not only resulted in killing 24 enemy without loss to his force, but were an inspiration to all in the Battalion. During this period his personal courage under fire was directly responsible for two significant successes. In one of them, in which he was wounded, the CO of the enemy force battalion was killed.