The Bhaichung Bhutia-owned side put up a valiant fight to hold the Federation Cup winners to a goalless stalemate in the first-half that included few misses from East Bengal.
But East Bengal made amend in the second-half as Ralte scored the winner through a freekick in the 82nd minute for their first win of the season.
Ralte's shot from the left side of the penalty box took the deflection from Budhiram Tudu to enter the USFC net that settled the issue.
East Bengal, who were held by Sporting Clube de Goa in their first round fixture, now have three points from two matches, same as the local outfit who had won their first round match against Salgaocar.