Right arm pacer Harvinder first dismissed opening batsman Dheeraj Jadhav to cut short a fine innings before striking two vital blows in the afternoon session to drive a wedge through the Rest innings.
The young Rest side, having elected to bat on a placid track, eventually were all out for 223 half an hour from close.
In reply, the Ranji Trophy champions were three for no loss with Amit Pagnis on two and captain Sanjay Bangar on one at the crease.
The hosts owed their happy day at office also to left arm spinner Murali Kartik whose two key strikes opened the floodgates after a solid first wicket stand between Jadhav andGambhir.
Also coming good was off-spinner Kulamani Parida who, after a dismal season last year, proved his good form by wrapping up the tail to finish with four for 61.
Railways' coach Vinod Sharma was all smiles at the end of the day.