Japanese Uchiyama has now made seven successful defences of the belt since winning it from Mexican Juan Carlos Salgado in January 2010.
The 33-year-old's professional record stands at 20-0-1 (17 KOs), while that of Venezuelan Parra, 30, now reads 20-1-1 (10 KOs).
In another Venezuela v Japan battle on the card, Liborio Solis won the WBA super-flyweight belt with a majority decision over interim champ Kohei Kono.
Solis, 31, was declared the winner by two of the three judges (115-111, 114-112), while the third scored it a draw (113-113).
Home fighter Kono, 32, was making his first defence having won the title from Thai Tepparith Kokietgym in December.
Solis improves to 15-3-1 (7 KOs) while Kono is now 28-8-0 (11 KOs).
- Sports & Recreation