Outside hitter Alireza Abdolhamidi delivered another strong performance, leading the Iranian team with 18 points (16 kills, one block, one ace), followed by opposite Ali Hajipoor, who left the court with 14 (12 kills, two blocks).
Outside hitter Maicon Franca and middle blocker Pietro Santos scored eight points each for Praia.
The destination of the second Pool A spot in the semifinals will be determined on Friday, when second-placed Cucine Lube Civitanova of Italy, which has four points, meet third-placed Al Ahly SC, of Egypt, which has three.
The winner will face Trentino for a spot in the gold medal match.