This knight shouted three warnings to Lancelot not to cross, but Lancelot was deeply engaged just then in the knightly duty of contemplating his lady, and his horse was thirsty. As soon as Lancelot’s mount was in the water drinking, the guardian of the ford rode in and knocked the oblivious champion from his saddle.
At last awake to his immediate situation, Lancelot demanded to know the reason for this attack, swearing he had never heard the other man. Not that it would have made any ultimate difference, of course, but the knight of the ford put up a better than average fight before Lancelot, blaming himself for weakness, got his opponent on the run. At length the guardian’s damsel intervened, helping her knight obtain first mercy and then freedom (by the rules, Lancelot could have taken him prisoner).
The damsel even risked rape by promising to do Lancelot whatever favor he desired, but he released her from this pledge and carried away the good wishes of both. The whole episode seems irresistibly burlesque.