He participated in Chiang's communist extermination campaigns, was given command of First Army in 1936, and took part in the Battle of Shanghai and Wuhan, variously leading the Seventeenth Army, 34th Army Group, 8th Military Region and 1st Military Region. Hu proved himself in these battles and along with Tang Enbo, Xue Yue, and others, Hu became one of the Kuomintang generals his enemy deeply feared and respected. However, Hu's glory on the battlefields was short-lived, and much to the delight of his Japanese enemy, Hu nearly vanished after these battles and rarely participated in the rest of war because he was put in charge of more than 400,000 Kuomintang troops by Chiang Kai-shek to blockade the communist base in Shaanxi. Hu Zongnan would have preferred to die for his country on the battlefields fighting the Japanese invaders, even the communist agents infiltrated his inner circle would have to admit that Hu had shown his eagerness to fight the Japanese from time to time, but as a professional soldier, he dutifully carried out his order given by Chiang Kai-shek by staying at this job for the rest of war.