Felix Limo led a Kenyan clean sweep as he won the Chicago Marathon on his debut appearance on Sunday.
The 25-year-old, who finished in a time of two hours, seven minutes and four seconds, beat Benjamin Maiyo by just seven seconds and Daniel Njenga by 10.
Evans Rutto, another Kenyan, could not make it a third successive victory as he came home in fourth in 2:07:30.
Deena Kastor, America's Olympic bronze medallist, won the women's race in 2:21:24 for her first major title.
Defending champion Constantina Tomescu-Dita, of Romania, came second, at 2:21:29 and Masako Chiba of Japan was third in 2:25:59.
Britain's Kathy Butler finished an excellent seventh on her debut over the distance.
The 31-year-old clocked 2:30:01 to move into second place in this year's British rankings behind Paula Radcliffe.