Local boy and IM R. Raja Rithvik shocked GM Boris Savchenko of Russia, the top seed, on the third board in the fifth round of the Tetrasoft Hyderabad Marriott International Grandmasters chess tournament here on Friday.

In the biggest upset of the day, Rithvik opened with Nf3 and the Russian Grandmaster replied with d6. The game followed d4-g6 on second and c4- Bg7 on third moves.

But, after the 33rd move by Savchenko with black pieces — B x d5 — Rithvik got the clear advantage. Soon, to the delight of the Hyderabad boy, Boris committed another blunder — Be4 — which compelled him to resign after 60th move.

On the top board, IM Alexandr Triapishko of Russia preferred the King Pawn opening against GM P. Karthikeyan, who replied with g6. After the 64th move with black — Rx e3 — the Russian converted what looked to be a draw into a win.