The retreat had begun in June, when Cossack cavalry under Andrei Shkuro raided the insurgents' capital of Huliaipole and drove Makhno's anarchist army westward across Ukraine. Falling back hundreds of kilometers, the insurgents briefly allied with the ataman Nykyfor Hryhoriv, then turned on and killed him for his ties to the Whites and his role in antisemitic pogroms, a reminder that this was a war fought amid terrible violence against civilians. Reinforced by defectors from a collapsing Red Army, Makhno's forces kept moving until they reached Uman, then held by the Ukrainian People's Republic, which agreed to shelter their thousands of wounded on neutral ground. Dug in outside the town, surrounded and short of everything, the insurgents finally decided they had run far enough.

The battlefield was a maze of deep ravines and dense forest, hemmed by the Syniukha River and crossable at only a few points. The White Volunteer Army attacked on September 22, meaning to finish the insurgents for good, and for days the fighting swayed across the high ground. Then a White gap opened. Makhno regrouped his forces and, on the night of September 26, launched a feint that drew the enemy west before striking east in the dark. The battle proper began at three in the morning, and at first it went badly, the insurgents pressed back to the edge of Peregonovka, readying a last stand by nine. The turn came when Makhno personally led his cavalry in a flanking charge, sabres out, into a far larger force, breaking it in close combat and turning the fight into a rout.

The retreat that followed was a catastrophe for the Whites. Chased by insurgent cavalry and running out of ammunition, they fell back toward the Syniukha, where men drowned trying to cross under fire, and whole units were destroyed; one battalion's commander shot himself after his last men fell. It was, for the losers, an annihilation. But the victory was decisive far beyond the riverbanks. Splitting up to seize as much ground as they could, the insurgents swept across southern and eastern Ukraine within days, took the rail network, and cut the supply lines of Anton Denikin's White advance on Moscow, which had reached to within 200 kilometers of the Russian capital. Historians credit the defeat here at Peregonovka with breaking Denikin's campaign, and with it a chapter of the war itself.