SAPPORO (Japan) (AFP) - Asian Games silver medallist Kiyoko Shimahara of Japan won the Hokkaido marathon on Sunday with Kenya's Daniel Njenga taking the men's title. Shimahara, whose previous best finishes were second in the 2004 Tokyo and 2005 Hokkaido marathons, pulled away from teammate Akemi Ozaki at the 12-km mark and crossed the finishing line in two hours 25 minutes and 10 seconds.Ozaki was never in a position to challenge Shimahara's lead and had to settle for second place in 2:27:23, ahead of Satoko Uetani in 2:33:55."I feel relieved that I finally won a race," said Shimahara after setting a new personal best and meet record. "I was among the men's runners in the same group and I was able to run in good rhythm. Even if I was caught up, I just planned to run at my own pace. I've been feeling pretty well, so I was determined to win," she added. Njenga upped his pace after passing the 10km point and finished in 2:12:03, beating Japan's Ryo Yamamoto into second in 2:12:10 and Laban Kagika of Kenya into third in 2:12:24. Njenga was at one point sitting on a more than 30-second lead, but Yamamoto and Kagika steadily closed the gap in the last two kilometres to put the pressure on Njenga, who finished only narrowly ahead."I started feeling pains in my right leg after 20 kilometres and I was not sure how far I could run. I've been struggling with my leg in the last two weeks," said Njenga, 33. "So I'm really happy to win the Hokkaido marathon at my first attempt," he added.