The Iranian team defeated Czech Republic 3-0 (29-27, 25-18, 26-24) in Pool C.
Pouria Yali led Iran with 20 points, while Feiz Emamdoost scored 10 points for Behrouz Ataei’s team.
Iran had previously defeated Tunisia 3-0 and lost to Russia 3-2 in the pool.
The 2019 FIVB Volleyball Men's U-21 World Championship is being held in Riffa, Bahrain from 18 to 27 July 2019.
A total of 16 teams from the 5 confederations compete in the tournament.