Former world champion Viswanathan Anand regained sole lead after a long drawn 1.5-0.5 win over Spaniard Alexei Shirov in the seventh round of the 12th Amber Blindfold and Rapid chess tournament in Monte Carlo.

With four rounds to go, Anand has 9.5 points and leads the overall standings by just half a point over Israeli Grandmaster Boris Gelfand.

The Indian ace also leads in the Rapid category with 5.5 points out of the possible seven, while Gelfand and Russian GM Vladimir Kramnik share the lead in the Blindfold variety with 5.5 points apiece.

In the Blindfold playoff, Anand faced the Petroff in his game against Shirov. Routine exchanges led the game to a level position and a draw was agreed to after 39 moves.

In the Rapid variety, Anand tried the Petroff against an out-of-form Shirov, but he kept the game evenly balanced.     However, Shirov went haywire as the endgame surfaced and lost a pawn in the rook ending. Anand did not let go the opportunity and wrapped up the game in 73 moves.

In the overall standings, Linares champion Peter Leko of Hungary, Kramnik and Bulgarian Veselin Topalov with 8.5 points jointly hold the third place, behind Anand and Gelfand.

In the Rapid standing, Russian Evgeny Bareev is half a point behind Anand.

Gelfand joined Kramnik at the top of the Blindfold table by defeating Bareev in the Blindfold variety. Both the leaders have 5.5 points apiece, followed by Topalov on 4.5. Anand and Leko share joint fourth spot on 4 points each.

Gelfand scored over Bareev in the Chelyabinsk variation of the Slav defense.

Playing white, the Israeli GM maintained a slight advantage in the middle game and capitalised on an erroneous endgame plan by Bareev to net a pawn. Gelfand soon drew the Rapid to win the mini-match.

Erstwhile leader Peter Leko met his nemesis in defending champion Alexander Morozevich and went down 0.5-1.5, losing the Blindfold, while Kramnik had a 1-1 draw with Ukrainian Vassily Ivanchuk after both games ended in truce.

Topalov scored over lowly placed Ljubomir Ljubojevic 2-0 to move up in the standings.

Results (Round 7):

Blindfold: Viswanathan Anand drew Alexei Shirov (Esp); Vassily Ivanchuk (Ukr) drew Vladimir Kramnik (Rus); Alexander Morozevich (Rus) beat Peter Leko (Hun); Boris Gelfand (Isr) beat Evgeny Bareev (Rus); Loek Van Wely (Ned) drew Zoltan Almasi (Hun); Ljubomir Ljubojevic (Yug) lost to Veselin Topalov

Rapid: Shirov lost to Anand; Kramnik drew Ivanchuk; Leko drew Morozevich; Bareev drew Gelfand; Almasi drew Van Wely; Topalov beat Ljubojevic.

Standings (after round 7):

Blindfold: 1-2. Kramnik, Gelfand 5.5 each; 3. Topalov 4.5; 4-5. Leko, Anand 4.0 each; 6-8. Morozevich, Ivanchuk, Van Wely 3.5 each; 9. Almasi 3.0; 10. Shirov 2.5; 11. Bareev,  2.0; 12. Ljubojevic 0.5.

Rapid: 1. Anand 5.5; 2. Bareev 5.0; 3-4. Leko, Morozevich 4.5 each; 5. Topalov 4.0; 6. Gelfand 3.5; 7-9. Kramnik, Almasi, Ivanchuk 3.0 each; 10-11. Shirov, Van Wely 2.5 each; 12. Ljubojevic 1.0.

Overall Standings: 1. Anand 9.5; 2. Gelfand 9.0; 3-5. Kramnik, Leko, Topalov 8.5 each; 6. Morozevich 8.0; 7. Bareev 7.0; 8. Ivanchuk 6.5; 9-10. Almasi, Van Wely 6.0; 11. Shirov 5.0; 12. Ljubojevic 1.5.