Hellen Obiri, a two-time Olympic silver medalist in the 5,000 meters, won the women’s race in 2:21:38 to complete the Kenyan sweep. Amane Beriso of Ethiopia was second, 12 seconds back, followed seven seconds later by Israeli Lonah Salpeter.

Kipchoge finished sixth — just his third loss ever in a major marathon to go with 12 victories. Scott Fauble was the top American, finishing seventh. Chebet is the first back-to-back winner since Robert Kipkoech Cheruiyot won three in a row from 2006-08.

Chebet was in a lead pack that dropped Kipchoge around Mile 20, shortly after he missed his bottle at a water station. A threesome pulled away with about three miles left, with Gabriel Geay of Tanzania winning a footrace for second, 10 seconds behind the winner and two seconds ahead of 2021 winner Benson Kipruto of Kenya.

Hellen Obiri breaks the tape at the finish line to win the women’s division of the Boston Marathon.

(Charles Krupa / Associated Press)

“Most of them blew up. Even Eliud Kipchoge blew up,” Fauble said. “I almost caught him.”

Marcel Hug of Switzerland won the men’s wheelchair race in a course record time — his sixth victory here — and American Susannah Scaroni won her first Boston title despite having to stop early to tighten a wheel that began to wobble on the bumpy pavement.

For the first time, the race also includes a nonbinary division, with 27 athletes registered.

Kipchoge had been hoping to add a Boston Marathon victory to his unprecedented running resume. The 38-year-old has won two Olympic gold medals and four of the six major marathons; Boston is the only one he has competed in and failed to win. (He has never run New York.) He also broke 2 hours in an exhibition in a Vienna park.

Fighting a trace of a headwind and rain that dampened the roads, Kipchoge ran in the lead pack from the start in Hopkinton until the series of climbs collectively known as Heartbreak Hill. But to the surprise of the fans lined up along Boylston Street for the final sprit, he wasn’t among the three leaders.

A dozen former champions and participants from 120 countries and all 50 states were in the field of 30,000 running 10 years after the finish line bombing that killed three people and wounded hundreds more. The race also included 264 members of the One Fund community — those injured by the attack, their friends and family and charities associated with them.

The city marked the anniversary in a ceremony on Saturday.