Ireland's Robert Heffernan just missed out of a medal in the 50 kilometre walk at the Olympics as he finished fourth in a national record of three hours, 37 minutes and 54 seconds.
Russia's Sergey Kirdyapkin won the gold medal in an Olympic record time of 3hrs 35min 59secs, almost a minute clear of Australia's Jared Tallent, who took silver for the second Games in succession, with China's Si Tianfeng claiming bronze.
Heffernan held off Russia's Igor Erokhin on the line as both athletes were given the same time.
The Irish athlete finished ninth in the 20km walk seven days ago and was also fourth in both walks at the European Championships in Barcelona in 2010.
The 34-year-old said: "I wanted to win an Olympic medal, it's been my dream. I did everything I could, it's hard to take to finish fourth. The last four years have been aimed at winning a medal at the Olympics so it's tough.
"The first 30km was just making sure I was refuelling, making sure I had the reserves to challenge on the last 20km. I had to be mature because you can get carried away by the unbelievable crowd.
"I stuck to the plan and it's just unfortunate I did not win a medal. There's nothing more I could have done."