India had been the only country ever to win kabaddi gold at the Asian Games until Iran shocked them five years ago.
Now India are gunning for revenge in Hangzhou but Iranian athletes and officials warned Monday they will face a "tough" battle to wrest back the gold.
Kabaddi, rooted in Indian mythology, requires two seven-player teams to send raiders into enemy territory to tag an opponent before returning to safety -- all on one breath and taking no more than 30 seconds.
Iran won both the men's and women's golds at the 2018 Asian Games in Jakarta to stun India, where millions of television viewers watch glitzy and money-spinning professional kabaddi leagues modelled on cricket's IPL.
But Iran are confident they will retain supremacy if the countries meet again in a medal showdown in Hangzhou this week.
"We come for gold," Iranian player Mohammadreza Shadlouichiyaneh told AFP after beating Pakistan 43-16 in their opening group match on Monday on the courts at Xiaoshan Guali Sports Centre.
"Our team's defence have a good performance, but their raiders are also very good. I think we can control them," he said.
"If we play in the final (against India), this is very hard and tough match, because both teams are strong," said Iranian coach Ghilamreza Mazandarani.
Only two players from Iran's victorious 2018 squad are playing in Hangzhou, Fazel Atrachali and Mohammadesmaeil Nabibakhsh.
But Mazandarani said this year's team "has a good combination in both sides, in defence also good, raid side also we have good talent."
India are determined to grab back their traditional status as number one in a sport that is revered back home.
"Our team will fight and our team will win," India women's coach V. Tejaswini Bai said after a surprise 34-34 draw against Taiwan in their first group match on Monday.
"Today we were a little bit nervous, but from now on we will be more relaxed," she added.
Kabaddi made its Asian Games debut in 1990 at Beijing with India winning every Asiad until Jakarta.
It has undergone a money-spinning makeover in recent years, with businesses and Bollywood stars paying big money to recruit players for their franchise teams, and millions of television viewers tuning in to watch.