Sofia, Apr 29 (IANS): Defending champion Viswanathan Anand dealt Veselin Topalov a huge blow with a novelty and a win in the fourth game to go 2.5-1.5 up in the 12-game World Chess Championship match.

In a game that showed Anand’s ability to take mind games to his opponent’s camp, Anand used a opening that Vladimir Kramnik had used to torment Topalov.

The duo will meet again in fifth game on Friday.

Anand, playing with white pieces, played the Catalan once again and came with a novelty as early as the tenth move (10. Na3) and pegged Topalov’s moves to the queenside and made him squirm and finally give up after 32 moves.

It was in some senses a typical Catalan but White had full compensation. Into the game post 25th move, Anand was all set to launch his attack in a preparation that he seemed to be comfortable in. Yet he took his time before going all out.

With Topalov's pieces tied, Anand launched a huge sacrificial attack on the king and carried it to through a fine win.

Once Anand unleashed his novelty on move 10, Topalov went into a long think and then played a move that showed Anand had prepared well and thereafter went on to demolish his opponent.

Topalov's pieces gradually got tied up on the Queenside and far away from his king. Anand went for a sacrificial attack and won the game.

Thus far white pieces have produced three wins in the match so far.