Hastings subsequently assumed command of the 6th Squadron after its commander, Major Charles Dick, was wounded in the assault on Destroyer Hill, which opened the way to Table Top and allowed the New Zealand Infantry Brigade to seize Rhododendron Ridge in preparation for the attack on Chunuk Bair. The Wellington Infantry Battalion under Lieutenant Colonel William George Malone managed to secure the summit of Chunuk Bair in the early hours of 8 August, and took heavy casualties throughout the day until reinforced by the Otago Infantry Battalion and the Wellington Mounted Rifles Regiment in the evening. Promoted in the field to major, Hastings commanded the 6th Squadron on Chunuk Bair on 8 and 9 August as the New Zealanders attempted to hold the position against fierce Ottoman counterattacks. Casualties were heavy and on the morning of 9 August Hastings was wounded when a bomb exploded, shattering his leg. His evacuation was significantly delayed by the terrain and congested approaches to the heights, and the dangers encountered by his stretcher bearers, but he was successfully admitted to the casualty clearing station down on the beach.