A 400lb American sumo wrestler hopes to become certified as the heaviest man to finish a marathon after competing the Los Angeles race in nearly 10 hours.Kelly Gneiting, who was the last of 11,891 men to cross the Los Angeles marathon finish line on Sunday, described the race as "pure hell".Gneiting walked the last 18 miles, suffering through painful blisters, but beat his 2008 time by two hours.He has won three US sumo titles beginning in 2005. "I did it, but it was hell," Gneiting, 40, was quoted as saying by the Los Angeles Times. "Pure hell."Gneiting of Arizona weighed in after the race at 396lb (179.6 kilos) four less than when he started, local television reported.By the time Gneiting finished the first half, the city had begun reopening streets along the route and he completed the race on the pavement, NBC television reported.Gneiting hopes to have his time - nine hours and 48 minutes certified by the Guinness Book of World Records.Source: orange.com