Vladimir Kramnik of Russia retained sole lead following a draw with Magnus Carlsen of Norway in the other game of the day.
With just two rounds to come in the four-players double round robin event, Kramnik remained at the top of the tables with eight points in his kitty in the football-like scoring system that gives one point for a draw and three for winning a game.
Anand inched himself up to six points with one victory and three draws while Shirov took his tally to three points with his third draw in the category-22 tournament. Carlsen is currently lying in the last spot with just two points, earned through two draws.
Anand could have joined Kramnik at the top had he spotted winning continuation in the middle game against Shirov. Playing white, the Indian was pleasantly surprised to see Shirov go for the risky McCutcheon variation in the French defense and went for the kill right from the early stages of middle game.
The World champion rolled his pieces excellently for the major part of the game and got the break through he was looking for on the king side that saw Shirov's king in mortal danger.
Though the nature of the position was tense, Anand came up with a fine 19th move to turn the tide in his favour. After the King manoeuvre black suffered huge troubles and had problems in finding solutions.
However, luck was not on Anand's side as he missed a win twice, first on the 23rd move and later on the 28th when the Indian ace in fact ended up blowing his chances completely.
"Perhaps I should have played positionally," Anand said after the game, "but I was looking for forced lines too much. If you miss one move, you get punished."
The World Champion referred to a moment where he could put his queen and knight on black squares and then push the rook pawn.
When asked about the game Shirov said, "It was a game that suits my style, yes, but as long as I'm in good shape, which is not the case in this tournament."
Carlsen almost lost his third game in the tournament and Kramnik could have been far away from anyone's reach. The Russian faced the English opening as black and Carlsen's do-or-die approach did not come good.
Kramnik won a pawn and reached a complicated endgame that should have been won but resolute play by Carlsen helped the Norwegian salvage a half point.