While the morning column was being cut to pieces three miles down the road, the men left in Johnson's camp could hear the fighting coming toward them and used the time. There was no fort, just an army in the open at the head of the lake, so they built a wall out of whatever they had. They threw up a rough barricade across the front of the camp made of their own wagons, overturned bateaux (the flat-bottomed boats they had carried up the lake), and trees felled and dragged into a line, and behind it they set their three cannon. It was not much. But it was cover, and at the Monongahela it had been the men without cover who died.

The retreating survivors of the morning came pouring back into the camp around the middle of the day with the French close behind, and Dieskau came on fast, hoping to ride the rout right over the barricade before the defenders could steady. Early in that first rush Johnson himself was hit, a ball through the hip and thigh that stayed in his body for the rest of his life, and he was carried to the rear, out of the fight. Command of the defense passed at once to his second, Major General Phineas Lyman (British) of Connecticut, and it was Lyman who stood at the wagons and ran the long afternoon's fight while Johnson was being doctored. Under him the provincials behind the barricade held, and the assault that should have been a single rush turned into something Dieskau had not bargained for, because his own army would not move.

The reason was the same reason that haunts this whole battle. The barricade in front of the Caughnawaga Mohawk was held by Mohawk: their own kinsmen, the warriors who had survived the morning and fallen back into Johnson's lines. The Caughnawaga refused to storm it, just as they had refused to fall on Fort Lyman the day before. They would not charge a wall defended by their own relatives. The Abenaki would not advance without the Mohawk, and the Canadian militia would not advance without the Native warriors, and so the great mass of Dieskau's force simply stopped at the edge of the woods and would not close. The kinship that ran underneath the imperial flags reached up at the decisive moment and froze a third of the French army in place. There is a tradition, resting on a single source and so to be held lightly, that Johnson's Mohawk had sent word to the French-allied Iroquois days before and used a signal of three gunshots to declare they meant their kin no harm; whatever the truth of that, on the field the kin would not kill kin.

That left Dieskau with only his regulars willing to attack. To shame the others into following, he formed his French grenadiers into a column six men abreast and sent them straight at the barricade up the open ground, in the European way, ranks closed and dressed. It was the bravest and the worst thing he could have done, because it gave the British cannon exactly the target they wanted. The provincial gunners loaded with grapeshot, a charge of small iron balls that turns a cannon into an enormous shotgun, and fired into the packed column at close range. The grape tore lanes through the grenadiers, what one account called lanes, streets, and alleys cut through the French. The men who had been steady in front of musket fire could not stand in front of that.

Across the field Dieskau was worse off than his rival. He was wounded in the legs, and then, propped helpless against a tree to keep directing his men, he was shot again, a wound he said pierced his bladder. With its general down and its grenadiers shredded by the grape and its allies unwilling to close, the French assault came apart and the survivors began to fall back down the road they had come up.

They left their wounded general behind. About twenty badly hurt French regulars were abandoned on the field, Dieskau among them, unable to move. He was taken prisoner, and the danger to him then was not from the provincials but from Johnson's own Native allies, who had watched their sachem killed and scalped that morning and had every reason to want a French general's life in return. Lieutenant Daniel Claus, a junior officer on Johnson's staff, stayed with the captured Dieskau and guarded him from them. The commander who had marched south to take the corridor in one stroke ended the day a wounded prisoner in the camp he had failed to carry.