Japan's Kaori Yoshida made a winning debut while 2003 world bronze medallist Masako Chiba finished a lowly 11th in her last career race at the Hokkaido marathon yesterday.
Yoshida made a break away shortly before the 15km mark against fellow Japanese Chika Horie and Tomoko Shimokawa before a long stint running solo to clock two hours 32 minutes 52 seconds in the women's event.
Her compatriots Mai Tagami and and Sachiyo Yamada came in second and third, while meet record holder Chiba timed 2:48:58. Shimokawa was fifth in 2:43:01 and Horie stopped running at the 27km mark.
The men's race was won by defending champion Tomonori Watanabe, who posted a time of 2:17:50 to lead a Japanese 1-2-3 finish with Mitsuru Kubota and Yusuke Kataoka.
Kubota's time was 2:17:53 and Kataoka 2:18:16.
"At the beginning I felt so comfortable, because I was really looking forward to my first full-distance marathon. I felt like I could beat even male runners," said Yoshida, 25.
"But in the middle of the race my feet started feeling heavy and when I crossed the finish line I was close to collapsing. But, overall, I am full of joy that I have run my first marathon," she added.
While Yoshida never faced a serious challenge, Watanabe had to overcome a deficit of more than one minute behind front-runner Toshihiro Iwasa of Japan who ran alone until the 37.8km point.
Then Watanabe formed a three-man group with Kubota and Kataoka before spurting after the 40km mark to stage a cat-and-mouse battle with Kubota.
Watanabe spurted again with 500m left and kept a narrow lead till the finish line.
"I like a race in hot conditions, but it was too hot today. It was very close until the last 50m. I just tried to run my best to win. I'm glad I made it," said Watanabe, 30.
"I felt comfortable in the first 30km, but it was tough after the three of us made the front-running group, because I started to think about winning the race. I just tried to calm myself down," he said.
"I'm not mentally strong enough. It gives me confidence that I was able to run tenaciously. We'll have the world championships at home next year. I'm going to do my best in a qualifying race for the worlds," Watanabe added.