Indian chess star Viswanathan Anand suffered a shock loss to next World Championship challenger Magnus Carlsen of Norway in the fifth round and slipped to the joint seventh spot in the Tal Memorial Tournament here.

Playing the last classical game against Carlsen ahead of the World Championship match scheduled in Chennai in November next, Anand could not find any suitable plan and was outplayed by the young Norwegian in what could be termed as a rude wake up call for the Indian world champion.

Boris Gelfand of Israel joined Hikaru Nakamura of United States in lead on 3.5 points after winning his second game in the tournament at the expense of Alexander Morozevich of Russia.

While Nakamura played his first draw in the tournament sharing point with Dmitry Andreikin of Russia the most striking thing known past the half-way stage is the fact that the four Russian participants are yet to score a victory in the tournament.

With Gelfand and Nakamura in front, Carlsen and Mamedyarov are close behind on three points each. Andreikin and Fabiano Caruana of Italy share the fifth spot on 2.5 points while Anand and Karjakin are joint seventh now on two points each.

Results round 5: Magnus Carlsen (Nor, 3) bt V Anand (Ind, 2); Boris Gelfand (Isr, 2.5) bt Alexander Morozevich (Rus, 1.5); Hikaru Nakamura (Usa, 3.5) drew with Dmitry Andreikin (Rus, 2.5); Shakhriyar Mamedyarov (Aze, 3) drew with Fabiano Caruana (Ita, 2.5); Vladimir Kramnik (Rus, 1.5)  drew with Sergey Karjakin (Rus, 2).