The 34-year-old Indian was qualified for the final round after shooting 122 with a series of 25,24,24,25 and 24.
Manavjit missed two birds in the final but held his nerve to hit the remaining 16 targets to grab the gold with a point's margin. His total final score was 145 (122+23).
Manavjit had recently won gold in the Commonwealth Shooting Championships at Delhi with a score of 146 (124+22).
"I did not realise that I was going to win until the last shots. It has been a very close competition. I just won by a single target. I shot aggressively up until the end and eventually made it to the top," Manavjit said.
"I am planning to take part in most of the ISSF World Cup stages, this year," added the 2006 World Championship gold medallist.