Essentially, the Americans established a very strong defence of the creek to prevent the British crossing the three fords; however, they failed to spot a British flanking attack that had crossed further along the Brandywine Creek. This is where the battle starts, with the British appearing on the edge of the American right. The map below shows the American dispositions along the creek:
Only at the last minute did the Americans deploy forces onto the high ground on their right to counter this threat.
The British flanking force consisting of Grenadiers, artillery and line troops comes into view and heads towards the Americans deployed on the high ground:
This is where the action is concentrated, with a stiff fight for the slopes, but the Americans are quickly overwhelmed and pull back:
And they engage the Americans across the river: