Norwegian world chess champion Magnus Carlsen defeated the title challenger, India's Viswanathan Anand, in the sixth game of their world title match at Sochi in Russia on Saturday.
With two connected passers on the king's side for Carlsen and down by whopping three pawns at the end of 37th move, Anand had no other option but to resign.
At the end of the sixth game, Carlsen leads the 12-game match 3.5-2.5.
For Anand the defeat will be doubly painful as he missed out a winning 26th Nxe5 move from a position that was very difficult to defend.
"No it can't be termed a game of blunders. But it is rare that two top notch players making successive wrong moves. The pain will be more for Anand as his error cost him a win from a very difficult defensive position," World number 23 and Indian Grandmaster P Harikrishna told IANS.
But what is true is that the sixth round of this world title match would be known as 'Ne5' game that brought down Anand.
Carlsen opened the game moving his king pawn two squares to which Anand responded with c5 the Sicilian defence and surprised the experts by opting for the Kan variation pushing his pawn to a6.
The first exchange of pieces happened on the 8th move with Carlsen exchanged his knight for Anand's queen side knight.
The next move Carlsen went for exchange of queens and in the process disturbed Anand's castling chances while pinning down the latter's white bishop to its home square.
The exchange of queens prompted Susan Polgar, a four-time women's World chess champion to tweet: "Basically white has very little initiatives in this line. Slow squeeze coming."
She was referring to Carlsen's specialty of playing a long grinding game while the opponent tires out.
Incidentally in round 4, Anand playing black, stopped Carlsen's attempts to exchange the queens. In that game it was because of the queen that Anand was able to exert pressure on the champion and go in for a draw.
In move 12 Anand exchanged his black bishop for Carlsen's remaining knight.
At this juncture, Carlsen's had an open position whereas Anand's pieces were somewhat cramped for want of squares for mobility.
"It was surprising that Anand went for this variation. It gives a passive position. I didn't expect the Kan variation. Further Carlsen chose the main line," Harikrishna said.
"Something went wrong for Anand in the opening. Maybe he was unprepared and bluffed, or he forgot his lines, or his team didn't analyse this variation properly," World number 3 Grandmaster Anish Giri told IANS.
So, can Anand draw the game with his Kan variation was the question in the minds of experts and others.
Meanwhile Carlsen started building pressure moving his rook to d3 square and then to g3 targeting Anand's king side pawns. His other rook enjoys free movement as the h file was already open.
Anand who started to lag behind on time started defending his king's side bringing his queen side rook to g8 square and his other rook rooted to its home square h8.
In 18th move Anand had his knight and rooks on f8, g8 and h8 squares whereas Carlsen's pieces had several squares to move around -- certainly not a pleasant position.
"At this moment Carlsen has a pleasant position. I wouldn't be pleased to be in Anand's shoes in this position and that too against Carlsen," Harikrishna said.
He said Carlsen will be calling the shots and it will be either a white win or a slogging draw for the black.
"The chances of a black win is remote unless Carlsen makes a blunder," added Harikrishna.
However Carlsen did blunder when he moved his king to d2 square on his 26th move giving Anand a chance bring his knight to active play capturing two white pawns and also giving a check to opponent's king as a bonus.
The position not only got simplified with a rook exchange but would have ended with Anand having great end game position.
But Anand made many a heart skip when he played a4 and later regretted the move. After that it was a slow painful death for the Indian.
"It was a logical game up to a point when the shocking blunder happened. It is really shocking of course, no way around it," Giri said.
"It is a big blow in any way you look at it. Hopefully Anand will recover and the fight will continue."
With Sunday being a rest day, the next round will be on Monday with Carlsen again having the advantage of playing white.
