Wijk Aan Zee, The Netherlands:Grandmaster P Harikrishna shocked top seed Arkaditsch Naiditsch of Germany in group B while World Champion Viswanathan Anand settled for a draw with American Hikaru Nakamura in group A in the fourth round of the Corus Chess tournament here.
Anand took his fourth consecutive draw before the first rest day and the Indian ace will now have to start winning a few games as Alexei Shirov is simply running away from this field.
The Latvian born Spaniard recorded his fourth victory at the expense of Dutchman Jan Smeets and is now a full point ahead of nearest rivals Nakamura, Magnus Carlsen of Norway and Sergey Karjakin of Ukraine.
Ahead of the first rest day, Anand stands joint fifth in the company of defending champion Sergey Karjakin of Ukraine, Leinier Dominguez of Cuba and Vladimir Kramnik of Russia.
Harikrishna caused a big flutter in the group 'B' defeating Naiditsch with awesome ease. Playing the King's Indian attack with white pieces, Harikrishna did everything right.
Routine manoeuvres in one of the popular variations led to a passive position for Naiditsch on the King side and the Indian crashed through with a timely piece sacrifice.
Knocking down pawns thereafter Harikrishna got as manyas four pawns for the sacrificed piece and won in 42 moves.
The other Indian in the group B, Parimarjan Negi however continued to search for an elusive victory as he too, like Anand, played his fourth successive draw.
Playing white against Wesley So of Philippines, Negi faced the Sicilian defense and early queen exchange led to a balanced position. Further exchanges led to simplifications resulting in a drawn rook and pawns endgame. The game lasted 37 moves.
Ni Hua of China and Anish Giri of Holland continued to share the lead in this section after drawing their mutual encounter.
While the two leaders have three points out of a possible four, Harikrishna stands joint third along with David Howell of England and Erwin L'Ami of Holland.
Parimarjan shares the sixth spot currently. Former World junior champion Abhijeet Gupta split point with Peng Zhaoqin of Holland in group C.
World junior girls' champion Soumya Swaminathan however succumbed to her third defeat in four games when she went down to top seed Li Chao of China.
Grandmasters Ray Robson and Li Chao share the lead in this section having 3.5 points apiece.
The lead margin is big as Abhijeet shares the third spot here currently along with local hopefuls Robin Swinkles and Zhaoqin, Daniel Vocaturo of Italy and Kjetil Lie of Norway.
The battles in all groups will resume on Thursday after the first rest day of the events.