Grandmaster Koneru Humpy, who suffered a shock defeat in the first game of the World Chess Championship semifinal, bounced back superbly beating Woman Grandmaster Ekaterina Kovalevskaya of Russia in the second game to push the match into tie-breaker here today.

The tiebreaker will be played later tonight under rapid chess rules.

In the other semifinal, Grandmaster Antoaneta Stefanova of Bulgaria advanced to the final ousting former World Women Champion Maia Chiburdanidze of Georgia.

Maya also went out in the semifinal stage in the last World Championship in 2001 against eventual champion Zhu Chen of China.

After squandering a winning chance in the first game, the Indian was back to her basics and played the do-or-die second game with absolute concentration. She was also assisted by lady luck, according to experts.

It was a Bogo-Indian defence that gave Humpy, playing white, a tangible advantage and slowly she started exerting pressure on the queenside after trading the queens in the early opening.

Though the queen-less middle game offered sufficient counter play to Kovlevskaya, Humpy was instrumental in forcing the Russian to part with a pawn.

Thereafter, Kovalevskaya played quite well and had enough compensation for the lost material. But with the clock ticking away she committed a positional blunder on the 27th move that spelt her doom.

The wily Indian soon coordinated her pieces and easily won a second pawn that was part of the erroneous package offered by Kovaevskaya. Soon it was curtains for the Russian after further simplification took place. The game lasted 51 moves.

After levelling the scores at 1-1, Humpy looked absolutely relaxed and went to her room to prepare for the tie-breaker.

The Bulgarian Stefanova has had some resounding success in this event so far and she now awaits the winner of the Humpy vs Kovalevskaya match after a rest day on Wednesday.

The Bulgarian gave an emphatic display to beat Chiburdanidze, who did not handle her white pieces well enough. It was an irregular opening choice by the Georgian that surprised even Grandmaster Vlimir Georgiev, Stefaova's second here.

Chiburdanidze was on the receiving end immediately after the opening phase and found her pieces stranded on the wrong squares resulting in the loss of a pawn. Playing in copy-book fashion Stefanova did well to keep Maia's forces in check on the king side.

At the same time she continued with her demolition act on the other flank that netted her two more pawns.

To hasten the end, Stefanova sacrificed her rook for a Bishop and this allowed her pawns to create havoc. Chiburdandze's efforts to pull off the near impossible went in vain and she was forced to resign after battling for 55 moves.

Results: Semifinal Game 2

Koneru Humpy (Ind) beat Ekaterina Kovalevskaya (Rus) 1-1, goes to tiebreak;
Antoaneta Stefanova (Bul) beat Maia Chiburdanidze (Geo).

The moves -- Game 2
Koneru Humpy v/s Ekateina Kovalevskaya
1. d4 Nf6 2. c4 e6 3. Nf3 Bb4+ 4. Nbd2 O-O 5. a3 Be7 6. e4 d5 7. Bd3 dx4 8. Nxe4 Nxe4 9. Bxe4 c5 10. O-O f5 11. Bc2 cxd4 12. Nxd4 e5 13. Nb5 Be6 14. Qxd8 Bxd8 15. Rd1 N6 16. Be3 a6 17. Nd6 Be7 18. Nb7 Bxc4 19. Ba4 Nd4 20. Bxd4 exd4 21. Rxd4 Bf7 22. Rad1 Bf6 23. Rb4 Rab8 24. Bc6 Rfc8 25. B3 Rc2 26. b3 Rc3 7 Nc5 Rd8 28. Nxa6Rxd1+ 29. Bxd1 Kf8 30. Kf1 Bd5 31. f3 Be7 32. Rb5 Be6 33. a4 f4 34. Ke1 Bf6 35. Nc5 f5 36. Kd2 Ke7 37. a5Bd4 38. Ne4 Bxe4 39. fxe4 Rc7 40. b4 Be3+ 41. Kd3 Rd7+ 42. Rd5 Rd5+ 43. exd5 Kd6 44. Bf3 Bf2 45. Kc4 Be1 46. Kb5 Kc7 47. Ka4 Kd6 48. b5 Kc5 49. b6 Bc3 50. d6 Kxd6 51. a6 black resigned

Maia Chiburdanidze v/s Antoaneta Stefanova
1. c4 Nf6 2. d4 c6 3. Bf4 Qb6 4. Qd2 Ne4 5. Qc2 d5 6. f3 Qa5+ 7. Nd2 Nxd 8. Bxd2 Q8 9. e3 g6 10. Bd3 Bg7 11. Ne2 dxc4 12. Bxc4 Nd7 13. Bb3 a5 14. a3 e5 15. O-O O-O 16. Rad1 exd4 17. Nxd4 Qe7 18. Rfe1 Ne5 19. e4 c5 20. Nb5 c4 21. Ba4 Nd3 22. Re2 Nxb2 23. Rb1 Nxa4 24. Qxa4 c3 25. Be3 Bd7 26. Qc2 Rfc8 27. a4 Rc4 28. Bc1 h5 29. Ba3 Qe6 30. f4 Qg4 31. Bd6 Bxb5 32. axb5 Rd8 33. e5 Qxf4 34. Rf1 Qg4 35. h3 Qe6 36. b6 a4 37. Kh1 Rd7 38. Ra1 Kh7 39. Rf1 Rc6 40. Ref2 Qb3 41. Qe2 Rxb6 42. Qe4 Rc6 43. Rb1 Qc4 44. Qc2 b5 45. Rff1 Rcxd6 46. exd6 Rxd6 47. Rf2 Bh6 48. Rbf1 Rd7 49. Rf3 Bd2 50. Rf6 a3 51. Ra1 Ra7 52. Rd6 a2 53. Rd8 Bg5 54. Re8 b4 55. Qf2 Rc7 white resigned.