Joana took the title despite being eliminated in the Nazaré Pro bodyboarding championship, the seventh and penultimate heat in the world circuit held on Sunday on Praia do Norte.
The married athlete, who studied in Lagos and lives in Sagres, achieved the feat seven days after her 30th birthday.
This year she also won the European circuit for the fourth time.
Born in Faro, one of four daughters of German parents Ute and George, Joana becomes the first Portuguese citizen to win a world title on a professional surfing circuit.
A lover of nature and animals and vegetarian since the age of 10, Joana says she has always been “obsessed” with the sea.
Speaking to the press after the heat, she said “I have no words to describe this moment. It hasn’t hit home yet. It’s incredible.”
The Algarvian athlete said “this is the top objective of any athlete and it can only be achieved with a lot of work over many months.”