There was another surprise in store when top seed and local favourite GM Surya Sekhar Ganguly had to concede half point settling for a draw against an unheralded R A Pradip.
Second seed Ivan Popov of Russia on the other hand had it easy against N R Visakh in a minor piece ending which arose from a Sicilian defence.
Playing white, Chennai boy Vignesh was up against the Benoni opening of Pantsulaia.
Vignesh defended with grit and obtained a passed pawn on the queenside which he used as a decoy to create a mating attack with his queen and bishop.
Also Read
The Georgian Grandmaster in his bid to avoid a draw faltered and was forced to give up on the 56th move.
Surya won a pawn early in the middle game but could find a way to crack open the fortress-like structure of his opponent and went on to sacrifice a pawn later in a minor piece ending to liven up the proceedings.
Former National champion IM Nisha Mohota held GM Gagunasvili Merab of Georgia in a rook and bishop versus rook ending where she had the extra bishop for 3 pawns.
Indian veteran Grandmaster Praveen Thipsay went down to 16-year-old G Lasya of Andhra Pradesh with the black pieces.
Former Bengal champion Kunal Kumar Chatterjee held 11th seed GM Azer Mirzoev of Azarbaijan to a draw in a Reti opening with the White pieces in 52 moves by perpetual checks.
Top Board Results
R A Pradeep Kumar (0.5) drew GM Surya Sekhar Ganguly (0.5); GM Ivan Popav (1) b N R Visakh (0); N R Vignesh (1) b GM Levan Pantsulaia (0); GM Deep Sengupta (10) b M Kunal (0); FM Debraj Chatterjee (0) lost to Ter Sakhayan Samvel (1); GM Vladislav Borovikov (1) bt Prantik Roy (0); Ram S Krishnan (0) lost to GM Dzhumaev Marat (1); GM Sanikidze Tornike (1) bt Pratik Patil (0); IM Nisha Mohota (0.5) drew GM Gagunasvili Merab (0.5); IM Mikhail Mozharov (1) b B Kumaran (0); K K Chatterjee (0.5) drew GM Azer Mirzoev (0.5); GM Valeriy Neverov (1) bt Akash PC Iyer (0); IM Stopa Jacek (1) b Kiran Manisha Mohanty (0); Arindam Mukhejee (0) lost to IM Arghyadip Das (1); GM Niaz Murshed (1) bt Dhulipala Bala Chandra Prasad (0).