Mo Farah spent the first few laps of the 10,000m at Rio chilling at the very back of the pack before finally getting on his horse—during an NBC commercial break, natch—and pulling a last-to-first move. He eventually settled down to fourth place or so for the meat of the race, and found himself boxed in with other runners, including his training partner, American Galen Rupp.Farah was running just ahead and to the right of Rupp and in the tenth lap, Rupp's foot clipped Farah's and he went crashing down to the track. It was an obvious accident; you can see Farah give Rupp a thumbs up after he got back up in the video above. A Ugandan runner had to hurdle him but otherwise there was enough room that Farah was able to pick himself up quickly and without further incident."When I fell down," Farah said, "I was just thinking, 'Try to get up, try to get up. Don't panic, don't panic, don't panic.' And then I got up, and I tried to just get through it."He added: "As soon as I got up, I was hoping the guys didn't see me fall down. They did make a bit of a surge. I thought, it's O.K., it's O.K., I still have quite a long way to go. If it happened five laps to go, six laps to go, I think the race would have been over."The race was not over, however, until Farah turned in an absurd final lap of 55 seconds. He pulled away from Kenyan racer Paul Tanui with a final 100 meter time of 13.3 seconds. He successfully defended his Gold in the 10,000m from London and will look to do the same in the 5,000m next Saturday.