Bilbao (Spain): World Champion Viswanathan Anand was stunned by Veselin Topalov of Bulgaria in the fourth round of the Bilbao Grand Slam final chess tournament.

On a day that provided decisive games in this category 22 event, 17-year old Magnus Carlsen of Norway became the unofficial world number one after beating Teimour Radjabov of Azerbaijan. Armenian Levon Aronian defeated Vassily Ivanchuk of Ukraine in a long drawn affair. (PTI)