Paralympic champion David Weir warmed up for Sunday's London Marathon with fourth place in Boston.
The Briton, competing in the race for the first time, finished in a time of 1:26.17, just over two minutes behind Swiss winner Marcel Hug (1:24.06).
Hug edged out South Africa's Ernst van Dyk and Australia's Kurt Fearnley in a sprint finish.
American Tatyana McFadden maintained her dominance to win her fourth women's title in a row.
Weir will be bidding for a record seventh title in London this weekend but will again be up against Hug, van Dyk and Fearnley in a strong field.
In 2012, Weir, 36, equalled Baroness Tanni Grey-Thompson's record of six London victories.
Since then, he has finished fifth in 2013, was beaten into second by Hug in 2014 and lost out to Joshua George 12 months ago.