Jouini started fast in the opening round, but it was Pritchard who finished stronger to take a 4-3 lead.
The Tunisian made no mistakes in the second round as she fought back to edge in front by one point.
However, the balance of power continued to seesaw as the Kiwi dominated the third round 5-1 to regain the initiative.
She was helped by the referee, who issued Jouini with a public warning for failing to heed his instructions.
Jouini applied the pressure in the final round and landed a big right hook that sent Pritchard down, although the referee did not deliver the count.
In the end, Pritchard ran out a 15-10 winner.