At the signal the two hidden parties leapt to their feet, and with levelled pikes rushed towards the ford. The English had no force there to resist the attack, for as the men-at-arms had passed, each had ridden on to join the fray in front. The head of the ford was therefore seized with but little difficulty. Orr, with twenty men, remained here to hold it and prevent others from crossing, while Macpherson, with fifty, ran up the hill and fell upon the rear of the confused masses of cavalry, who were striving in vain to break the lines of Archie's spears.

The attack was decisive; the English, surprised and confused by the sudden attack, were unable to offer any effectual resistance to Macpherson's pikemen, and at the same moment that these fell upon the rear, Archie gave the word and his men rushed forward upon the struggling mass of cavalry. The shock was irresistible; men and horses fell in numbers under the Scottish spears, and in a few minutes those who could manage to extricate themselves from the struggling mass rode off in various directions. These, however, were few in number, for ninety were killed and seventy taken prisoners. St. John himself succeeded in cutting his way through the spearmen, and, swimming the river below the ford, rejoined his followers, who had in vain endeavoured to force the passage of the ford. With these he rapidly retired.