Grandmaster Krishnan Sasikiran held top seed Emil Sutovsky of Israel to an easy draw in the seventh round of third Marx Gyorgy Memorial Grandmasters' Chess tournament in Paks, Hungary.
Grandmaster Viktor Korchnoi, the 74-year-old from Switzerland, regained sole lead with a thumping victory over former world junior champion Peter Acs of Hungary in the category-15 double round-robin event.
The Swiss took his tally to an enviable 5.5 points out of a possible seven and is half a point clear of his nearest contender, Zoltan Almasi of Hungary, who drew with compatriot Ferenc Berkes in his seventh round game.
Sasikiran and Sutovsky remain joint-third with three points each after a none-too-eventful draw, while Berkes improved his position marginally to move to fifth position on 2.5 points.
With just three rounds remaining, Acs is at the bottom of the table on two points.
It turned out to be a rather tame day for Sasikiran, who could do little with his white pieces against a well-prepared Sutovsky.
Choosing the English opening, the Indian faced a transposition to the Grunfeld that was swiftly declined.
A couple of pieces got traded very early in the middle game and, in fact, there was some pressure on Sasikiran as his queen was a bit misplaced after a fine plan by Sutovsky.
However, the game never really breached the boundaries of equality and the players agreed to sign peace in just 21 moves.
It was a similar story for Berkes, as white, against Almasi. The symmetrical set-up by the senior Hungarian against the English opening offered no scope to Berkes and, surprisingly enough, he decided for a rather premature end of the game by taking a draw in just 17 moves when only one pawn had been traded.
However, Korchnoi had no such plans and he went for a full-fledged battle against Acs.
Up against the open Ruy Lopez that has been the noted ammunition in Korchnoi's arsenal, Acs simply went haywire in the early stages of the game itself after his opponent went for a risky plan. Korchnoi wrapped the issue in 55 moves.
Results (Round 7): Emil Sutovsky (Isr, 3) drew with Krishnan Sasikiran (Ind, 3); Peter Acs (Hun, 2) lost to Viktor Korchnoi (Sui, 5.5); Ferenc Berkes (Hun, 2.5) drew with Zoltan Almasi (Hun, 5).
The moves:
Krishnan Sasikiran vs Emil Sutovsky
1. Nf3 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. Qa4+ Bd7 6. Qh4 Nxc3 7. dxc3 Nc6 8. e4 e5 9. Bg5 Be7 10. Bc4 h5 11. h3 f6 12. Be3 g5 13. Qg3 h4 14. Qh2 Bd6 15. Qg1 Qe7 16. Nd2 Nd8 17. Qf1 Bc5 18. Bxc5 Qxc5 19. Nb3 Qb6 20. O-O-O Ne6 21. Be2 Nf4 draw agreed.