Sanmartean and Al-Nadhri scored for the Saudi team in the 15th and 74th minutes respectively at the Sultan Qaboos Sports Complex in Muscat, Oman.
Elsewhere, Uzbekistan’s Lokomotiv won Group A after they drew 0-0 with Al Nasr in Tashkent.
Already eliminated Sepahan picked up a solitary win against Al Nasr on Matchday Two, and the Iranians made little impression throughout the 90 minutes with Abdollah Karami capping a miserable season for the club when he was sent off six minutes from time.
Tasnim News Agency - sports