Smart Capture Form - insert record into Salesforce

I have a Cloud Page with a Smart Capture form. The Smart capture form works as intended and stores the information into a specific Data Extension.

In addition to that, I would like to capture the POST data via AMPSCRIPT upon submission(or after) and insert a Lead record in Salesforce with CreateSalesforceObject function. How do I do this? It doesn't seem to work with normal IF RequestParameter(" Submitted").

Any advise is highly appreciated (but I would like to keep the Smart capture form as it's more user friendly.