Purushothaman, Natarajan shock GMs Paraguay, Evgeny
Top seed GM Aleksej Alexandrov of Belarus escaped narrowly against Praveen Kumar as the youngster failed to get his act together and allowed the title favourite to wriggle out with a draw.
Eighth seed GM Mark Paraguay of Philippines wasn't so lucky and was beaten by Purushothaman while 15th seed Podolchenko was stunned by Natarajan.
Sixth seed Abhijit Kunte was held to a draw by Ram S Krishnan, 10th seed Kirill Stupak also split points with Rakesh Kulkarni, Mithil Ajgaonkar held GM Raset Ziatdinov to a draw.
Ten players have emerged joint leaders with B Adhiban, Debashis Das, Natarajan, Purushotaman and V A V Rajesh being the Indians who have scored four points. Seventeen players follow half a point behind and tomorrow two more rounds are scheduled.
On the top board, Alexandrov enjoyed an edge in the Catalan opening but the Belarussian was strangely erratic in the middle-game and allowed a clear cut edge to Praveen Kumar.
Alexandrov's king was pulled out of his sheltered castle and his opponent's queen and rook threatened to catch the king in a checkmating net.
However Praveen Kumar also missed many winning positions and Alexandrov was forced to give up his queen for a rook and bishop. On the 53rd turn the Indian again missed a winning move and the game fizzled into a draw after 63 moves.
In a Modern Defence game, Purushothaman needed 51 moves to defeat Paraguay while the encounter between C Natarajan and Podolchenko lasted 35 moves of a Trompowsky Opening.
Important results of Round 4: IM Praveen Kumar (3.5) drew GM Aleksej Alexandrov (3.5); GM Andrei Deviatkin (4) bt IM Anita Gara (3); M Karthikeyan (3) lost to GM Nikolai Chadaev (4); GM B Adhiban (4) bt C R Krishna (3); GM Abhijit Kunte (3.5) drew Ram S Krishnan (3.5); GM Mark Paragua (3) lost to T Purushothaman (4); Saravana Krishnan (3) lost to GM Ziaur Rahman (4); GM Kirill Stupak (3.5) drew Rakesh Kulkarni (3.5); FM Debaraj Chatterjee (3) lost to GM John Paul Gomez (4); Sagar Shah (3.5) drew Vaibhav Suri (3.5); Rajesh V (4) bt Vinoth Kumar (3); Mithil Ajgaonkar (3.5) drew GM Raset Ziatdinov (3.5); GM Hoang Thanh Trang (4) bt Nimmy A G (3).