The Kenyan athlete Robert Kiprono Cheruiyot smashed the course record to win the Boston Marathon men's race, while Ethiopia's Teyba Erkesso captured the women's title by a few steps in a sprint finish.
In favourably cool conditions with a light wind, Cheruiyot, clocked two hours, five minutes and 52 seconds as he crossed the finish line, holding off Ethiopians Tekeste Kebede and defending champion Deriba Merga.
Cheruiyot took almost a minute and a half of the previous record set by Robert Kipkoech Cheruiyot in 2006.
In the women's race, Erkesso built a big lead going into the final few miles but was reeled in by Russia's Tatyana Pushkareva, which set up a furious sprint down Boston's Boylston Street to the finish line.
Erkesso won by three seconds in 2:26:11. Last year's winner, Kenya's Salina Kosgei, was third.
African men have won 19 of the past 20 editions of the 42.2 km race from Boston's hilly suburbs to its centre.