Overnight leader and sixth seed B Kumaran split points with seventh seed Sidhant Mohapatra, while Murali Karthikeyan outwitted Ritviz Pranab on the third board.
Three players -- Murali, Kumaran and Diptayan -- shared the lead with six points each after seven rounds.
Third seed Arvind Chithambaram (5) also kept himself in contention after a draw with Aradhya Garg (5).
Diptayan played his favourite English opening and built up some advantage in the mid-game by sacrificing his knight and a similar one in the end game caught Vijay (5) in the wrong position, where he had to concede the game in the 31st move.
With a win against Rutuja Bakshi (5) of Maharashtra, second seed WFM GK Monisha (6) of Tamil Nadu remained as one of the title contenders.