Ethiopian runners vying for a place in the summer Olympics have dominated the Boston Marathon, taking the top three spots in the men's division and the top two among the women.

Lemi Berhanu Hayle won for the men on Monday in a dramatic late surge against defending champ and fellow Ethiopian Lelisa Desisa, covering the notoriously hilly course in two hours, 12 minutes and 45 seconds, as thousands of spectators cheered him.

On the women's side, Ethiopian Atsede Baysa won in 2:29:19, overcoming a 37-second deficit in the last 8km of the race against training mate Tirfi Tsegaye.

Meanwhile, Australian wheelchair athlete Kurt Fearnley finished third, with Switzerland's Marcel Hug taking out the title after winning the sprint to the line.

It was the 120th running of the world's oldest continually run annual marathon, and the third since a pair of ethnic Chechen brothers killed three people and injured more than 260 with a bomb attack at the finish line.

Most top US marathoners sat out Boston to train for the Rio Games in August.

But Ethiopia and Kenya - whose runners dominated the lead packs - have yet to pick their teams for the Olympics and will consider the Boston results.

The 21-year-old Hayle won the race by pairing off with Desisa to break from the mainly East African pack late in the course. He then drafted off his countryman before surging past him in the final two miles.

Hayle's finish time was slower than the personal best of 2:04:33 he posted in Dubai earlier this year. The Boston marathon record of 2:03:02 was achieved by Kenyan Geoffrey Mutai in 2011.

Among the women, Baysa, 29, is among the world's most prolific marathoners and has posted top four finishes in five world marathon majors, including wins in Paris and Chicago.

Kenyan Caroline Rotich, who was defending her 2015 win in Boston and was widely seen as a favourite in Monday's women's race, dropped out early in the race.