Viswanathan Anand and Veselin Topalov played a quick draw in just 23 moves that kept the Indian ace still in second place with just one more round to go.
Anand needs to win his final round against Boris Gelfand, while Topalov should do no better than a draw against Peter Leko for Anand to get into a tie for top place.
Topalov has 8.5 points, while the NIIT Brand Ambassador has eight following the 12th round, in which six of the seven games ended in draws with Gata Kamsky beating Shakhryar Mamedyarov in the only decisive game.
Anand, with black, played a novelty and that earned him equality right in the opening after a Ruy Lopez start in Moeller defence.
Anand offered a piece sacrifice on the 13th move and since that did not offer anything substantial advantage for Topalov, the Bulgarian did not accept it. A draw was the best result. After a series of exchanges in an hour, the two agreed to a draw.
In the other games, Gelfand was lucky to get away with a draw against Vassily Ivanchuk, while Sergei Tiviakov drew with Peter Leko.
In round 11, Anand had drawn with Sergei Tiviakov, while Topalov drew with Ivanchuk.
Final Round 13:
Pairings for final round: Aronian v Sokolov; Ivanchuk v Karjakin; Anand v Gelfand; Leko v Topalov; Kamsky v Tiviakov; Adams v Mamedyarov; Bacrot v van Wely.
Results of Round 12: Topalov drew with Anand; Karjakin drew with Aronian; Tiviakov drew with Leko; Mamedyarov lost to Kamsky; Sokolov drew with Bacrot; Gelfand drew with Ivanchuk; Van Wely drew with Adams.
Standings after Round 12: 1. Topalov 8.5; 2. Anand 8.0; 3. Adams, Gelfand and Karjakin 7.0; 6. Ivanchuk 6.5; 7. Leko 6.0; 8. Tiviakov, Van Wely and Aronian 5.5; 11. Bacrot 5.0; 12. Kamsky 4.5; 13. Mamedyarov and Sokolov 4.0.