The organisers of the Great Ireland Run in Dublin have apologised after the 10 kilometre run was cut short by 1.5 kilometres.
2,000 people took part in the run in the Phoenix Park on Sunday, with plenty thinking they had clocked a personal best and two thinking they had smashed a world record.
However, it emerged they actually hadn't run the full 10km because of a mistake during the run.
It's understood participants were misdirected and didn't realise they were running the wrong way.
In a statement, organisers said:
"Athletics Ireland and the event organiser Dublin City Harriers wish to apologise to all participants for the unforeseen circumstances that led to today's Great Ireland Run (incorporating the national 10k championship) being less than the specified distance.
"Athletics Ireland will continue to engage with the race organisers on the matter and update national 10k championship participants when further information becomes available."