The 9th Infantry Division continued to advance against stiff but eroding German resistance.
By 27 July it was abreast of Marigny, and shifted right to allow the passage of mechanized and motorized sister units moving forward to exploit the penetration.
Some 200 Germans supported by tanks and anti-tank guns attempted a desperate last stand, but were swept away by the division’s advance.
The division cleared routes for the passage of armored divisions through it, and began mopping up residual enemy resistance in the breakthrough area as the armored divisions assumed the lead.

The German retreat turned into a rout as armored spearheads raced ahead.
Avranches fell during the night of 30 July, and Brecey on the 31st.
Having fulfilled its Cobra assignment, the 9th Infantry Division passed into reserve for rest and reconstitution.