Shootout for Olympic title of world\'s fastest man

The fastest man in the world will be crowned on day three of athletics events at the London Olympics, which starts on Sunday morning with the women\'s marathon through the city\'s streets. Barring unforeseen circumstances defending champion Usain Bolt of Jamaica and his training partner and world champion Yohan Blake will take centre stage in the blue riband 100m in a battle that promises to light up the Games. Bolt smashed the world record to win gold four years ago but comes into the race looking vulnerable after Blake edged him in the Jamaican trials in both sprints. Also expected to be in the hunt for medals are the likes of former world record holder Asafa Powell, also of Jamaica, and the US pair Justin Gatlin, the disgraced 2004 champion, and Tyson Gay, the second-fastest man in history. \"I am the Olympic champion and I have to show the world I am the best,\" Bolt, 25, said on the eve of the Games. Blake, crowned world champion in Daegu last year after Bolt sensationally false-started in the final, said: \"My philosophy is that the sky\'s the limit. I\'ve always wanted to be at the Olympics. It\'s everyone\'s dream.\" Sunday\'s athletics programme kicks off with the women\'s marathon at 11:00 am, starting and finishing in the Mall in central London, near Buckingham Palace, and taking in many of the city\'s most famous landmarks. The powerful Kenyan team features 2011 world champion Edna Kiplagat, last year\'s world silver medallist Priscah Jeptoo and Mary Keitany, the fastest woman in the world this year. But veteran British marathon runner and world record holder Paula Radcliffe was denied a swansong in front of her home fans when she was forced to withdrew with a foot injury. The Kenyans are also hot favourites to continue their dominance in the men\'s 3000m steeplechase, a race they have won in every Olympics dating all the way back to Los Angeles in 1984. Ezekiel Kemboi can become the second man after defending champion Brimin Kipruto in Beijing in 2008 to win the Olympic title as reigning world champion. Sunday\'s action also features the final of the women\'s 400m with world champion Amantle Montsho looking to become Botswana\'s first Olympic medallist, male or female, in any sport. The final is also likely to feature Great Britain\'s defending champion Christine Ohuruogu. Sunday also sees two field events -- the women\'s triple jump final and the final of the men\'s hammer throw. Caterine Ibarguen is looking to become the first athlete from Colombia to win an Olympic gold medal but standing in her way are the likes of Ukraine\'s Olha Saladuha, the 2011 world champion, and Kazakhstan\'s Olga Rypakova. One athlete not taking part in London is Belarus hammer thrower Ivan Tsikhan, who won bronze in Beijing and silver four years earlier in Athens, but is embroiled in an ongoing doping controversy. Events (finals) Men: 100m, 3000m Steeplechase, Hammer Throw