World champion Viswanathan Anand signed truce after failing to break Englishman Luke McShane's solid defenses while Magnus Carlsen defeated local hope David Howell to join the leaders after the fifth round of the London Chess Classic on Monday.
Anand and McShane are the only two undefeated players in the tournament following a draw between them while Carlsen benefitted from an oversight by Howell in the second time control.
Going by normal rules, Anand and McShane are the only two leaders but the soccer-like scoring system, which gives three points for a win and one for a draw, has put Magnus back on track for the title with three wins.
Anand and McShane have won two and drawn three which means that under normal scoring system they would tally three-and-a-half points each, half point more than Carlsen who has lost two games.
With all leaders on nine points, Vladimir Kramnik, who drew with English Michael Adams, shares the fourth spot along with American Hikaru Nakamura on eight points each.
Nakamura got the better of an out-of-sorts Nigel Short, who suffered his fourth defeat in the 145000 Euro tournament being played on round-robin basis between eight players.
Adams holds sixth place on six points while David Howell is on two, a full point ahead of back-ranker Nigel Short.
Anand pressed for advantage in the Berlin defense game but it seemed the Indian was much better in the middle game that ensued. McShane however remained on his guard right through and restored parity with some timely exchanges leading to a drawn queen and bishops endgame.
"These are trends, a month from now we may see them all switch over to something else," said Anand when asked about the Berlin defense that's in vogue here.
"I was better after the opening but it was just slightly better, if it was serious, I did not see it," the world champion said.
Carlsen defeated Howell from the black side of a Najdorf Sicilian. The Norwegian was in his elements post the second time control after Howell erred on the 43rd move and wrapped the issue quickly.
Kramnik faced the Kind pawn opening and it was another Berlin defense by the Russian. The alternative main line employed by Adams did not yield much as Kramnik equalized quickly and started looking for initiative.
Adams had to find some resources to let the game drift towards a draw.
Nakamura was pleasantly surprised to see Short employing a side variation in the Marshall Gambit. The American was on top in the middle game with an extra pawn and relished the endgame that arose after subsequent exchanges.
Short, who is going through a forgettable event, could not pose much of a challenge.
In the open event being organised simultaneously, 15-year-old International Master Sahaj Grover came back into the reckoning with a fine win over Nicolai Getz of Norway.
While Sahaj moved up to four points out of five games, Grandmaster Abhijeet Gupta remained on 3.5 after losing to Gawain Jones of England.
With four rounds still to go, Grandmaster Saptarshi Roy Chowdhury is also on 3.5 points and the lead is shared by Simon Williams of England and and Gavin Wall of Ireland -- both have five points each.
Results round 5: V Anand (Ind, 9) drew with Luke McShane (Eng, 9); David Howeel (Eng, 2) lost to Magnus Carlsen (Nor, 9); Michael Adams (Eng, 6) drew with Vladimir Kramnik (Rus, 8); Hikaru Nakamura (Usa, 8) beat Nigel Short (Eng, 2).