Library Eusebius of Caesarea Life of Constantine
Book 2, Chapter 17: Constantine's Victory.
But as soon as he perceived that his adversaries persisted in their resolution, and were already drawing their swords, he gave free scope to his indignation, and by a single charge overthrew in a moment the entire body of the enemy, thus triumphing at once over them and their gods.
English translation by Ernest Cushing Richardson, in Nicene and Post-Nicene Fathers, Series II, Vol. I (eds. Philip Schaff and Henry Wace; Buffalo: Christian Literature Publishing Co., 1890). Public domain. Digital text via New Advent Church Fathers.