Edna Kiplagat won the women’s race to complete the Kenyan sweep.
They were followed closely by Americans who grabbed two of the top four women’s spots and six of the top 10 for men – the first time that’s happened since the race went professional in 1986.
Rupp was 21 seconds back, and Japan’s Suguru Osako 30 seconds behind him.
"American distance running is looking good today," said sixth-place finisher Abdi Abdirahman, a Somali immigrant and Tucson resident who is a four-time Olympian.
Kenya had won either the men’s or women’s race every year since 1991 before being shut out in 2014 and again last year.
For Kirui, even when he was running shorter distances, he had his eye on Boston.
"In my mind, I was sure that one day I would win this race," said Kirui, 25, who was running just his third marathon.
Mr. Keflezighi, 41, said he plans to enter the New York Marathon, which he won in 2009, one last time in the fall before retiring.
Marcel Hug won Boston for the third time, outpushing 10-time champion Ernst Van Dyk down Boylston Street and finishing in 1:18:04 to beat the course record and world best by 21 seconds.
Evans, who completed his 52nd marathon overall, said he wanted to show that Boston is back to normal.