After winning the home leg 2-0, the Japanese team held Persepolis to a goalless stalemate in Iran to clinch their first-ever title in the tournament.
Almost 100,000 supporters crammed the Azadi stadium in Tehran to see their team overturn the first half deficit but Kashima's sensational rear-guard action left most of them frustrated.
Kashima defended stoutly right from the outset and limited the number of chances their Iranian counterparts could fashion.
Persepolis striker Ali Alipour did get some opportunities to score but he was wasteful with his finishing and could not capitalise. He fired wide from inside the box on one occasion before heading tamely at the Kashima goalkeeper at the half-hour mark.
A frustrated Persepolis saw Alipour miss another chance at the hour mark when he volleyed an effort well wide. Kashima's defence would stand strong to become the third club from Japan, after Gamba Osaka and Urawa Red Diamonds to win the AFC Champions League title.