Item Received on a Wrong PO but the Item was already Shipped Out via Sales Order to the Customer

Scenario:

Item#ABC1 was received off on a wrong PO#1 in our warehouse. It should have been received off from PO#2. Meanwhile, the item has been shipped out already to the customer via Sales Order.

PO#1 and PO#2 are for the same vendor. Invoice documents received is for PO#2.

Warehouse wants to reverse the receipt on PO#1 so Accounts Payable can pay the invoice for the correct PO#2.

Question:

Considering that the item was already shipped to the customer, how can PO#1 be reversed?

What's the best practice in the industry on how to handle this?

Any thoughts?

Thanks.