Short answers, pulled from the story.
The Battle of Taierzhuang was a major engagement of the Second Sino-Japanese War fought in the spring of 1938, during the Xuzhou Campaign. It was the first major Chinese military victory of the war, in which Chinese forces encircled and forced the retreat of two Japanese divisions.
The cramped urban terrain of Taierzhuang neutralized Japanese advantages in artillery, armor, and air power, forcing the fight into close-quarters infantry combat where Chinese soldiers could match the Japanese. Chinese forces also successfully encircled the Japanese attackers, severing their supply lines, while resupplying their own troops through the South Gate throughout the battle.
Estimates vary significantly. Western historians Peter Harmsen and Stephen MacKinnon put both Japanese and Chinese casualties at roughly 20,000 each. Frank Dorn, an American officer stationed in China between 1934 and 1939, recorded over 15,000 Chinese dead and at least as many wounded, for a total exceeding 30,000 Chinese casualties. In the 31st Division alone, only 2,000 of an initial 9,000 soldiers were fit for roll call after the battle.
The overall Chinese commander was Li Zongren, head of the KMT's 5th War Zone, headquartered at Xuzhou. The defense of the town itself was led by General Sun Lianzhong's 2nd Army Group, with the 31st Division under General Chi Fengcheng arriving first on the 22nd of March 1938. Tang Enbo's 20th Corps executed the encirclement operation that cut off Japanese supply lines.
Chinese defenders used German-made 37mm Pak-36 antitank guns, destroying 8 of 11 attacking Japanese tanks at point-blank range on the 1st of April 1938. Members of the "dare to die" corps also strapped explosives, grenades, and dynamite to their bodies and threw themselves under Japanese tanks to destroy them.
Taierzhuang was the first major Japanese defeat since the start of the war and broke what was widely called the myth of Imperial Japanese military invincibility. Li Zongren described the victory as "the first happy occasion since the war of resistance had started" and called the town "a symbol of national renaissance." Celebrations were held in Hankou and other Chinese cities, while Japan initially denied the defeat entirely.