Going in to the return game of the second round of this knockout championship with a point lead thanks to her victory in the opening game, Humpy won her fourth game on the trot to also keep a clean slate in the championship thus far.
Grandmaster D Harika was stretched to the tiebreaker by her American counterpart Irina Krush after the second game between them also ended in a draw. Harika will now play a set of two rapid games with 25 minutes each to determine the winner in this contest.
Should the deadlock continue, the players will play one Armageddon game with five minutes for white and four to black and black will proceed to the next round in case of a draw.
It may be recalled that the third Indian in the fray - Mary Ann Gomes was ousted from the championship losing the Armageddon game against Tatiana Kosintseva of Russia in the first round.
The biggest causalty of the round was second seed Wenjun Ju of China who was shown the exit door by experienced Natalija Pogonina of Russia.
Humpy proved a class act once again. Playing the white side of a Grunfeld defense, the Indian went for the Fianchetto variation that is in vogue. The position oscillated between equal and slightly better for Humpy and the exchange of pieces did not deter her to push for a decisive advantage.