The Union column led by Maj. Gen. William H. French's III Corps, followed by Brig. Gen. Gouverneur K. Warren's II Corps, approached Auburn about 4:15 p.m. French had dispatched his cavalry under Brig. Gen. H. Judson Kilpatrick to the north to guard his left flank from Confederate cavalry at Warrenton, leaving the column without the cavalry at its head, thus allowing it to stumble into the Confederates at Auburn. French and his staff, at the head of the column, fired their revolvers at the Confederates as the infantry and artillery were brought up. Lomax attempted to charge the Federal line but a volley of canister shot drove back the assault. By 4:45 the fighting died down, just as Lee arrived from Warrenton. Seeing they were facing two infantry corps, Lee and Lomax withdrew to Warrenton.