Double International Master norm holder Harshavardhan GB (5) upset GM Bogdanovich Stanislav (Ukraine) keeping his lead after the fifth round of the 12th Chennai Open International Grandmaster Chess tournament for Sakthi Group Dr. N. Mahalingam Trophy here on Tuesday. On top of the table with Harshavardhan were GMs Martinez Alcantara Jose Eduardo (Per) and Visakh N R (Ind) at 5 points each. Top seeded GM Ponkrantov Pavel (Russia) stood half a point behind the leaders at 4.5 points along with GMs Yudin Sergei (Russia), Neelotpal Das (India), IM Taher YosephTheolifus (Indonesia) and Pranav V (India). Harshavardhan GB, a student of Velammal School, Chennai continued his fine run defeating Ukraine GM Bogdanovich Stanislav in a Nimzo Indian game. With two IM norms under his belt, Harshavardhan is well on track to achieve his final International Master Norm here.