Double Olympic champion Mo Farah admitted he had been "seeing stars" before collapsing shortly after crossing the finishing line in an incident-packed New York City half-marathon on Sunday.
Farah recovered from a painful fall in the 28th minute of the race to finish second to Kenya's Geoffrey Mutai, but then passed out in the finishing area before being taken away in a wheelchair.
"I do remember sort of passing out," Farah told reporters at a post-race press conference.
"I tried so hard in the race, taking a fall and then going through. But I'm all right. It's fine. It's not a big deal."
The 30-year-old was in the leading pack of eight athletes when he was sent crashing to the tarmac after seemingly being accidentally tripped from behind. He quickly got back to his feet and resumed running, but Mutai took full advantage of the incident to accelerate and pull clear with compatriot Stephen Sambu.
"I would have done exactly the same thing if I was him in the race," Farah admitted.
Mutai, who clocked the fastest marathon time in history in Boston in 2011 and has six sub-60 minute half-marathon times to his credit, then eased away from Sambu on 42nd Street and went on to win in 60 minutes 50 seconds.
Farah slowly reeled in Sambu and eventually edged ahead with 800 metres to go before holding off the 25-year-old on the line to clock 61mins 7secs, just outside his British record of 60:59.
Speaking about his fall, Farah added: "I'm not sure what happened. I just remember sort of falling down and just hitting the ground quite hard. I got caught on my hip, my ankle, the whole right-hand side. At that point, I just wanted to get back up and get with the group.
"It did take quite a lot out of me. My aim was to just close the gap slowly, but I couldn't quite close the gap. And then the last four miles I struggled a bit. I was just pretty much seeing stars. Everything was kind of blurred to me. I just wanted to keep going. I didn't want to stop and drop.
"I couldn't quite get Mutai, but managed to get second place. I tried my hardest and gave 110 per cent. That's all you can do. Sometimes things happen out of your control and you've just got to move on.
"It doesn't make you a bad athlete. The guys are pretty decent athletes. It's not like Joe Blow or someone else who's beaten you today. They're both good athletes."
Farah was using the race as preparation for his full marathon debut in London on April 13 - also against Mutai - and will hope for warmer conditions there. The temperature in New York was around freezing and Farah began the race in long sleeves, a hat and gloves.
"Conditions today were very cold," he added.
"London's going to be different, but I felt good to the point I went down. It would have been nice to come out here and win the race, but Mutai's a strong athlete."