Then he charged into him and struck such a blow with his sword that he drove the sword more than a thumb's length through his helmet. And Mordred repaid him with the best blows that he could deliver with his arms. They worked each other over with their sharp swords until both of them were exhausted. But Mordred had the better of the battle, for he drove the knight around as he wished and fought so well that he pinned the other knight beneath him and removed his helmet from his head and said that he would kill him if he did not promise to do Mordred's will.

The Vulgate Cycle