V.R. Raghunath opened the scoring for India from a penalty corner in the 20th minute. But his opener was cancelled out just three minutes by a stinging shot from Andrew Cornick.
It was another penalty corner post-break that gave India the lead for the second time in the match. R. Singh was at hand in 42nd minute to turn the ball into the back of the net.
Gurwinder Singh Chandi put the match beyond Wales in the 47th minute from India's first open-play goal in the match.
India, who have been clubbed alongside Wales, Scotland, and South Africa besides world champions and reigning gold medallist Australia, will next take on the hosts Saturday before taking on mighty Australia July 29, followed by their last pool encounter against South Africa slated for July 31.