Negi was caught off-guard in the opening itself and never recovered while Sasikiran misplayed a promising position to lose to Korobov.
In the other game of the day, former World Junior Champion Abhijeet Gupta played out an exciting draw with top seed Radoslav Wojtaszek of Poland.
After a highly combative day in the Rs 12 lakh prize money tournament, Korobov joined Wojtaszek in the lead on two points from three games while Gupta, Negi and Alekseev now follow the two leaders a half point behind.
Luck-less Sasikiran is now alone at the bottom of the tables with just a half point from his three games.
With seven rounds still to come in the six-player double round-robin tournament, much excitement is to be expected if the first three rounds are anything to go by.
The no-draw-offer rule in place here is serving the cause to provide high-quality fighting chess, something the Indian Chess Federation and Airports Authority of India had hoped for when conceiving the idea.
Negi started with the Sicilian defense with black and it was surprising to see the extremely slow pace of the game against Alekseev. The Russian thought for a long time right from the beginning and Negi had to do the same after he made an error while trying to work out the plan in an unknown position. More
