The World No. 16 Indian, playing with black pieces, started off on a strong note to dominate the initial stages of the game.
"I surprised him with Benoni, a Fianchetto variation and after that move he was just trying to save the game," Harikrishna said after the match.
However, Harikrisha could not capitalize and Ernesto dug deep and clung on to draw the game that lasted for 47 moves.
At the end of the day's action, Harikrishna has one and a half points so far in this campaign after drawing three and losing just one and is placed 16th on the leaderboard.