Chennai: Viswanathan Anand and Magnus Carlsen produced a memorable clash in the World Chess Championship here on Wednesday.

The fourth game ended in a draw after 64 eventful moves and just under 6 hours of play.

Both contestants took the game to a superior level, straining over the board visibly. “This is the way chess should be played,” proclaimed Anand later on.

The score is tied at 2 -2 after four games, and the match will resume on Friday after a rest day. Terming the game as ‘tremendous’, English GM Nigel Short remarked, “The match has burst into flames!”

As the pressure increased with the complexity of the game, Carlsen was even seen mouthing a curse, when finding that his position wasn’t as promising as he hoped. Anand was frequently seen biting his nails and even muttering to himself, forced to defend a tense position for most of the game.

Carlsen later dismissed questions about Garry Kasparov’s visit to the venue with a sharp: “This match will be decided mainly over the board, not off it.” Bringing the attention back to the competition, he said: “It was a very good fight – I am happy.”

Abandoning the Caro-Kann defence in favour of a more solid system with Black, Carlsen resorted to the Berlin Defence of the Ruy Lopez, having a reputation of a dry way to face 1.e4. Carlsen said that he was “happy with the way the opening went”.

Curiously, the game followed an earlier game from Wijk aan Zee 2011 between Surya Sekhar Ganguly and Jon Ludvig Hammer, seconds of Anand and Carlsen respectively.

Anand’s 15.Rad1 was a theoretical novelty, played only in games between computers in the past. Anand confessed: “Something went horribly wrong in the opening, and I made one illogical move after another”.

The turning point in the opening came with 18.Ne2 after which Anand confessed that he was “basically lost”.

Anand allowed 18…Ba2 similar to Bobby Fischer’s pawn capture against Boris Spassky from their world championship match in 1972, to which the current match is frequently referred to in terms of importance. He still had Rooks doubled on the d-line and Carlsen’s King on the queenside seemed to give him long term compensation for the pawn.

But Anand’s previous challenger Boris Gelfand preferred Carlsen’s position at this point, saying: “Vishy played the opening unsuccessfully. He has only a slight compensation for the Pawn due to better piece co-ordination”. Anand looked visibly stressed at this point.

Between moves 22 to 25, Anand expanded his Pawns on the kingside as well as drove Carlsen’s Bishop to the passive c8 square, while Carlsen’s Rooks remained disconnected at a8 and h8.

However, Anand didn’t seem to have any clear plan of action. After the game, Anand pointed out 25…Ne7 was better for his opponent, which was probably the best possible moment for Calsen to have achieved a win.

Under pressure, Anand fought really well. Carlsen was all praise: “He kept finding resources. He just fought on really well.” As the position got messy and Carlsen’s advantage became quite unclear due to the position getting more and more complicated, Scottish Grandmaster Jonathan Rowson described the game as something when the players were out to ‘Punch each other on the faces without blocking’.

Carlsen’s winning try with 30…a5! was praised, but Anand made a wave of counterplay created with 35.Ne4, sacrificing the second pawn and complicating the position.

Curiously, this was suggested by Kasparov who considered it as the “only way to fight”, and proclaimed by the commentators as “the best move of the match so far”. GM Sethuraman said it was “not a human move”.