Riding on two goals from Adelaja S, Sikkim United beat Assam Regiment Centre 3-1 after coming from behind in the first encounter at the Ambedkar Stadium.
In the next game, Mohammedan Sporting too came out from an early set back to trounce Army Green 4-2.
S Adelaja (40th and 59th) and MD Lepcha (89th) scored for the Sikkim team after TS Workham Anal (19th) gave lead to the Assam side.
For Army Green, Sanaton Singh (5th) and Subrata Sarkar (52nd) found the net.
The winners of the group qualify for the semifinals.