Managing to ward away the threat posed by British strikers, the Indians survived early danger and then hung on to the lead they gained in the 17th minute through Mandeep Singh capitalizing on a fine centre from seasoned right winger SV Sunil at the Olympic Park's Lee Valley Hockey Centre.
Young drag-flicker Harmanpreet Singh unleashed a rasping shot to convert a penalty stroke in the 33rd minute to give India a 2-0 lead before Britain pulled one back through a penalty corner conversion by Ashley Jackson two minutes later.
The Indians then defended their citadel well enough to ward off further threat to their own goal.
"We saw some fine performances from the young players. They have given me a nice surprise," said Oltmans, who has rested several senior players with the aim of providing top-quality exposure to the juniors before picking the Indian side for the Olympic Games.
India's victory have given them four points from two outings, after their 3-3 draw with reigning Olympic champions Germany in the opening fixture. India are at par on points with World champions Australia, who yesterday defeated South Korea 4-2 for their first win in two outings.
Australia were held to a goalless draw on the first day by hosts Great Britain. Germany drew 4-4 with Belgium in their second match and now have two points from as many outings.
The Koreans have three points from their first fixture against Belgium, who have just one point from two matches. Oltmans said the Indian team was improving with every outing and that reflected in the good performance against Great Britain.
"We didn't start this match too well. We were struggling in the first quarter, but then we we took control of the game," Oltmans said.