Britain's David Weir missed out on a record-breaking seventh London Marathon win as he lost out in a sprint finish to American Joshua George.
Weir, 35, was in contention throughout and took the lead turning into the closing stages on The Mall.
But George, whose previous London best was seventh in 2008, powered through to win in one hour 31 minutes 31 seconds.
Tatyana McFadden made it a US double with a course record of one hour 41 minutes 14 seconds in the women's race.
The wheelchair races, as well as those for athletes with visual impairments and upper limb impairments, also double as the IPC Athletics World Championship Marathon events.
With Swiss rival Marcel Hug out of contention after the 15km mark with a puncture, six-time Paralympic champion Weir looked set to beat Baroness Tanni Grey-Thompson's record of six wins in the capital.
But George finished the strongest to come home a second ahead of Weir, with Masazumi Soejima of Japan third.
Weir admitted afterwards that he had a problem with his gloves around the 15-mile mark which hampered him from then on.
"My thumb came through the material so I was pushing awkwardly for the last 10 miles and it took a lot out of me as I had to change my technique," he told BBC Sport.
"But I don't want to make any excuses. Josh was awesome today and he pulled the field apart."
McFadden, who has won the Grand Slam of the four big city marathons - Boston, London, Chicago and New York - over the past two years, built up an early lead in her race and was never in danger.
The 26-year-old beat her previous course record by four minutes with Manuela Schaer of Switzerland second and McFadden's compatriot Amanda McGrory third.
Britain's Shelly Woods failed to finish.