Chinglensana Singh's own goal gave Jamshedpur the lead before skipper Peter Hartley and Daniel Chima Chukwu scored a goal each.
The 3-2 win helped Jamshedpur FC leapfrog Kerala Blasters to the third spot in the ISL 2021-22 points table. Mumbai City FC are fifth.
Manvir Singh broke the deadlock in the 3rd minute to keep ATK Mohun Bagan in the driver's seat before doubling the lead in the second half.
