World silver medalist Koji Murofushi on Sunday won the hammer throw competition at the Grand Prix II meet in Prague with a new Japan record of 84.86 meters -- the world's best mark this season.

News photo Koji Murofushi celebrates after recording the best hammer throw of the year and the third best of all time with a distance of 84.86 meters at the Grand Prix II meeting in Prague on Sunday.

With an 81.76 throw, Murofushi was the only one in a field of nine who cleared the 80-meter line in his first try before going on to set the third-best throw ever in his fifth attempt, eclipsing his own national record of 83.47 set in July 2001.

"I couldn't believe it. I thought it barely reached 83 meters. The throwing circle was slippery, but I took advantage of that. I pretended it was just another practice, where I always try and think of ways to better my personal record," the 28-year-old said.