Credit Processing

I recorded a credit memo for an item returned from a customer which had been payed for on a closed invoice. I applied the credit to a later invoice, where it showed properly. I have since received payment on the latter invoice for the balance due and closed it. The Credit Memo is still showing in the list of open invoices. I would have thought that applying it to an invoice would close it. How do dispose of it so it is removed from the open invoices report? Thank you.