On 13 June, he departed bound for Suez in Egypt, arriving 24 July. His unit took part, beginning on 6 August, in the Battle of Chunuk Bair, in support of the landing at Suvla Bay, which was intended to break the deadlock in the Gallipoli Campaign. The initial assault was successful and early on the morning of 8 August, Downing was with A Company occupying the Turkish trench on the crest of Chunuk Bair. The Turks counter-attacked at dawn, forcing back the British battalions and the Wellingtons. The crest was lost and the battle continued for 12 hours on the seaward slopes. By nightfall, Downing, who had earlier distinguished himself in a bayonet charge, was killed, reportedly "blown to pieces". Downing was the first of 13 All Blacks killed in the war, just a day before Henry Dewar, the second All Black to fall, was killed in action with the Wellington Mounted Rifles at Anzac Cove.