In 1380, Prince Dimitry Donskoy of Moscow came to seek St. Sergius` blessing before leading his army for the Orthodox faith and for the liberation of his native land from the Mongol yoke, which greatly oppressed Russia since 1237. Having received the saint's blessing to go against the godless enemies, the Grand Prince won a great victory over the army of the Tartar Khan Mamai on the Kulikovo Field on the 8th of September. It was the first major Russian victory against the Tartars. After that, Moscow Princes became the patrons of the Trinity monastery.

St. Sergius entrusted his holy and pure soul to God on September 25, 1392. His successor as abbot of the Trinity monastery was St. Nikon, first among his disciples.