The Indian ace now has four points out of a possible six and seems to be getting better as the tournament is progresses.
Veselin Topalov of Bulgaria strengthened his lead at the top with another victory at the expense of Alexander Grischuk of Russia.
The Bulgarian took his overall tally to 5.5 points with his fifth win in the strongest tournament of the year.
The other games of the sixth round ended in draws. Anish Giri of Holland played a long theoretical line yet again and drew with Levon Aronian of Armenia, Jon Ludvig Hammer of Norway signed peace with Fabiano Caruana of Italy while World champion Magnus Carlsen of Norway could not get past the solid defences of Hikaru Nakamura of the United States.
With three rounds still to play, Nakamura and Anand share the second spot on four points each while Anish Giri is alone in fourth spot on 3.5 points. The trio of Vachier-Lagrave, Aronian and Caruana are joint fifth on 2.5
points while Carlsen shares the eighth spot on two points each and Hammer is currently last with 1.5 points in his kitty.
Anand stole the day's honours with a brilliant game. It was a Bishop sacrifice out of a Sicilian Najdorf that caught everyone's attention in the middle game.
Interestingly, a similar sacrifice in the exact same variation had occurred in a recent top game between David Navara and Grischuk. And, as it turned out, both players were aware of that.
"We both remembered Navara-Grischuk, but I couldn't remember the details," said Anand.
"I couldn't make it work at first. I was surprised that he allowed it. It was a safe sacrifice, because I always had at least a draw."
There followed some amazing tactics, but in every single line White was winning.
"This is positional chess in the Sicilian!" joked Anand in the post-game chat.
Vachier-Lagrave agreed he missed the crucial point.
"I completely missed Bishop sacrifice," said MVL.
"I thought I was defending [against this threat] and suddenly I wasn't defending at all. I felt during the game I should be okay," he added.
Soon after Anand's game, Topalov defeated Grischuk.
Ten years ago Topalov won the FIDE World championship tournament
with 10/14, scoring 6.5/7 in the first half. Tis event is serving as a perfect reminder to all of that superlative performance.
In a Nimzo-Indian that quickly looked a bit like a Benoni, Grischuk basically blundered a piece as early as move 16.
“I am a bit surprised," said Topalov. "I don't think I'm playing that good but it's good enough to see that mistake."
The tournament leader remained modest about his score: "Sometimes it happens that you're getting all the luck in one tournament. I think that's happening here now."
Results, Round 6: V Anand (Ind, 4) beat Maxime Vachier-Lagrave (Fra, 2.5); Jon Ludvig Hammer (Nor, 1.5) drew with Fabiano Caruana (Ita, 2.5); Magnus Carlsen (Nor, 2) drew with Hikaru Nakamura (Usa, 4); Anish Giri (3.5) drew with Levon Aronian (Arm, 2.5); Veselin Topalov (Bul, 5.5) beat Alexander Grischuk (Rus, 2).
Image: Viswanathan Anand
Photograph: Getty Images