The Army man, who has already won a quota place for India in the Rapid Fire category, shot a score of 572/600 to tie for the lead with Yongde Jin of China.
However, Kumar’s tally of 17 inner tens to Jin’s 15 helped him bag the gold.
Kumar started with a score of 98 in the first series of 150 seconds for 10 shots. His scores dipped in the 20-second and the 10-second series and he reached the halfway mark at 284, two points behind the Chinese who tallied 286.
Vijay performed better in the second series with a tally of 288. Jin was in the lead but then had a disastrous score of 93 in the final 10-second series which saw him finish alongside Vijay.
The bronze was won by Tomohiro Kida of Japan, who shot 568.
But the other two Indian shooters in fray put up a disappointing show and were nowhere in contention for a podium finish. Samresh Jung shot 552 to finish 16th, while Mahavir Singh finished 24th with a score of 542. Those low scores ended India’s hopes of a team medal as well.
They finished fifth after a combined score of 1666/1800.
The gold was won by China with a total of 1695 while Thailand surprised everyone by clinching the silver with a tally of 1683 points.
Japan rounded of the podium finishers with a score of 1680.