After a goalless first half, Tolgay let go a right footer on target in the 59th minute, enabling the city giants keep intact their all win record in the fancied football league.
After five rounds, East Bengal are on 15 points, while Salgaocar - who lost their first points in the tourney - stayed on 12.
Salgaocar matched East Bengal in the opening half with their upfronters led by veteran Ghanaian Yusif Yakubu repeatedly troubling the local side's rear guard.
Japanese Ryuiji Sueoka muffed up a golden opportunity midway into the first season, much to the relief of the East Bengal supporters at the Salt Lake stadium.
East Bengal looked a transformed side in the second session, as they controlled the proceedings and their hard work was rewarded when Robin Singh's centre was put into the net by Tolgay.