Chopra won Olympic gold in Tokyo but managed only a silver at the worlds in Eugene last year. The only other Indian to win a medal at the worlds was Anju Bobby George, who took bronze in the women's long jump in 2003 in Paris.
Chopra soared into the lead on his second attempt with an 88.17 metre effort, with him turning his back and celebrating in trademark fashion with his arms aloft immediately after his throw, knowing it was good.
"This was great. After the Olympic gold I really wanted to win the world championships. I just wanted to throw further. This is brilliant for the national team but it was my dream to win gold at the world championships," Chopra said.
"This has been a great championships for India and I am proud to bring another title to my country. I don't think I am the best thrower here. I wanted to throw more tonight.
"I wanted to throw more than 90m tonight but it needs all parts of the puzzle to be there. I couldn't put it all together this evening. Maybe next time."
Pakistan's Nadeem, coming back from elbow surgery and a knee injury, produced his season's best effort of 87.82 on his third attempt to win the silver medal, while the Czech Republic's Jakub Vadlejch (32) took the bronze with 86.67.
