On 1 April 2016, heavy fighting broke out between the Azerbaijani and Armenian forces along the Nagorno-Karabakh Line of Contact, known as the Four-Day War. During the clashes, Hashimov served as Deputy Commander and Chief of Staff of the 1st Army Corps. He commanded the Azerbaijani forces stationed in Tartar District, and during night operations, his forces advanced towards Talish, capturing several strategic locations. He was wounded during the clashes. One of the military posts Hashimov seized near Talış was later renamed "Polad" in his honour. According to Turkish military expert Abdullah Ağar, the Azerbaijani military command ordered Hashimov to withdraw from the territories he had seized during the hostilities. After a ceasefire was reached on the front-line, Hashimov resigned immediately, but the president of Azerbaijan, Ilham Aliyev, intervened and did not allow him to resign.