A goal-line save by Stephanie de Groof from India's first penalty corner in the 36th minute ensured that the Belgians held on to the lead they had earned just a minute ago from a penalty corner conversion at the other end.
Indian goalkeeper Savita saved two shots from De Groof before Belgian captain Lieselotte van Lindt capitalised on the rebound with a diagonal shot into the net in the 35th minute.
The Indian women, who had grimly held on against some early Belgian raids, forced their first penalty corner within a minute of conceding the goal. Deepika Kumari's penalty corner drive was blocked by diving goalkeeper Aisling D'Hooghe, sending the round to captain Ritu Rani whose flick was heading into the goal, but for a diving clearance by De Groof.
The Indians, ranked one spot behind Behind Belgium's number 12 world ranking, pushed hard and created some openings, but the equaliser eluded them in the Group B match.
Against a team that fell back to bolster their defence, India managed to force a penalty corner in the 42nd minute, but the set-piece was not executed well and the ball got cleared.
The Indians had earlier successfully appealed for a back-stick to get a Belgian goal cancelled in the first quarter.
In the other Group B match, Gemma Flynn slammed four goals as New Zealand fired a dozen goals past Poland. Captain Anita Punt opened the account for the Black Sticks in their 12-0 triumph in the eighth minute before Flynn came into the frame with a flash strike in the 13th minute.
She was again on target through a field goal in the 15th minute and later scored two more goals in the 32nd and 47th minutes.
Punt fired her second goal in the 34th minute. Matching her two-goal feat was Olivia Merry (19th and 48th minutes).
World champions The Netherlands stamped their authority with a 11-0 triumph over France, who were confirmed a spot in the tournament after Azerbaijan's withdrawal, while Asian Games champions South Korea were held to a 1-1 draw by Italy in Group A.
Dutch captain Maartje Paumen converted three penalty corners and Lidewij Welten joined her with three goals as the French were swept off their feet.
South Korea, who have already secured a qualification for the 2016 Olympics by winning the gold medal at the Incheon Asian Games, surged ahead through a 10th minute field goal from captain Kim Jong-Eun, but Italy equalised two minutes from the final hooter from a penalty corner strike by Giuliana Ruggieri.
Image: Lieselotte van Lindt
Photograph: Sergio Moraes/Reuters