Great Britain's David Weir finished fifth in the men's T54 marathon at the Tokyo Paralympics as Switzerland's Marcel Hug took gold.
China's Zhang Yong claimed silver ahead of American Daniel Romanchuk, who crossed the line for bronze.
Six-time Paralympic champion Weir, 42, last won a medal in London 2012.
Hug and Zhang were neck and neck before the former pulled away to finish with a time of one hour 24 minutes two seconds.
Weir's fellow Briton Johnboy Smith came through in 10th position and Ireland's Patrick Monahan was 12th.
In the T46 category for athletes with arm impairments, Derek Rae was ninth in 2:47.04. The Scot had failed to finish his race in Rio and was hampered this time by injury after he suffered a stress fracture to his lower back in June.
'I don't know if this is the end or not'
An emotional Weir said he would consider his future in the coming weeks.
"I was still in with a shout for a medal and I was hoping, but I knew it was going to be tough, that last couple of miles, because Daniel is so good uphill," he told Channel 4.
"I left everything possible out on that course today so I'm just absolutely knackered now. I couldn't try any harder.
"I need to go back home and reflect on what I want to do. I've spoken to my team about certain things, I need to have a few weeks to think about things. Keeping up with Marcel is going to be mission impossible, maybe.
"There are things I'm working on when I get back. Let's see if that works. [Hug] did 1:24 on a wet course and he absolutely destroyed the field.
"It has been a long five years for me, I've had my dark moments where I didn't want to be here so to get here is just a mission. I'm proud of myself. I haven't been emotional, but today I knew I would be because I don't know if it is the end or not.
"I've got the London Marathon in a couple of weeks, I'll do my best again and sit down and reflect on what I want to do."
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