Pirouj registered a personal-best record of 69.74m in his third attempt, though it eventually proved not enough for the Iranian to improve on his silver medal in Tokyo three years ago, as Briton Dan Pembroke threw 74.49m with his fourth effort to smash the world record and retain his Paralympic title.
His throw bettered the previous record – set by Aleksandr Svechnikov of Uzbekistan in 2017 – by 3.48m.
Pembroke had already broken Svechnikov’s mark with an effort of 71.15m from his third throw.
Ulicer Aguilera of Cuba took the bronze with 62.51m.
“It was such a high-level event. The British athlete was brilliant today, though I didn’t back off and made my best-ever throw,” Pirouj said after the final.
“Pembroke broke the world record twice but I gave it my all till the end and am so disappointed to end my campaign with the silver,” added the Iranian, who also settled for back-to-back runner-up finishes to Pembroke in the past two World Championships.
Pirouj’s silver was a 10th para athletics medal for Iran in Paris.
Elsewhere at Stade de France on Thursday, Hassan Bajoulvand took the silver in the men’s discus throw F11 class, courtesy of a 41.75m effort – 17 centimeters adrift of Italian gold medalist Oney Tapia – with Spanish Alvaro del Amo Cano finishing on 39.60m for the bronze.
In the men’s shot put, Aliasghar Javanmardi grabbed the bronze in the F35 class with a best effort of 15.84m.
Uzbekistan’s Khusniddin Norbekov set a new Paralympic record of 16.82m to win the gold, with Hernan Emanuel Urra of Argentina throwing 16.11m for the runner-up spot.