Mohammadjavad Manavinejhad on 10 was the best scorer of Iran, but almost half the home side's points (29 of 63) came from unforced errors of France at the Hossein Rezazadeh Hall in Ardabil, Iran.
Clevenot with a match-high 15 points and Boyer with 11 led France's scoring.
Earlier on Sunday, Australia scored a massive win over Portugal 3-0 (25-23, 25-22, 27-25) as both teams continue their quest to avoid relegation.
The 2019 FIVB Volleyball Men's Nations League is the second edition of the FIVB Volleyball Men's Nations League, an annual international men's volleyball tournament contested by 16 national teams.
The competition is being held between May and July 2019 and the final round will take place in the Credit Union 1 Arena, Chicago, United States.
This is the first edition of the World League or the Nations League to have the Final Round hosted in North America.