RCF had their chances but they missed those, including a penalty stroke awarded in the 50th minute of play, which was muffed by right half Rozalind Ralte with a wide push at the Mahindra Stadium.
RCF, in fact, took the lead through a fine field goal by Anuradha Thokchom in the 23rd minute of play.
Northern Railways tried to turn the tide through incisive attack by the experienced duo of Ritu Rani and Rani Rampal. But it was a penalty corner, which finally yielded them the equaliser in the 48th minute when Harpreet Kaur scored by beating RCF goalkeeper Harmanjeet Kaur.
Finally it was the reverse hit by Poonam which gave Northern the title after four years. She moved in swiftly from left to hammer the ball home from a narrow angle much to the joy of her teammates.
In the all-Mumbai match for third position, hosts Central Railways surprisingly beat last year's winners Western 4-1.
Western led through a 17th minute goal by Anupa Barla but thereafter it was all Central with goals coming from Vandana Kataria (34, 45th), Saundarya (44th) and Kavita Vidyarthi (62nd).