Yomif Kejelcha broke the men's world half marathon record in Valencia on Sunday, the Ethiopian clocking 57min 30sec to shave a single second off the previous mark.In his sixth appearance over the distance, the 27-year-old world indoor mile record holder took control of the race from the three-kilometre mark.Kejelcha passed through 5km in 13:38, 10km in 27:12 and 15km in 40:56 when he broke away from Kenyan pair Daniel Mateiko and Isaia Kipkoech Lasoi to secure victory and beat the world record set by Jacob Kiplimo of Uganda in Lisbon three years ago.In the women's race, Agnes Ngetich of Kenya was also on world-record pace in the early stages, but her speed dipped slightly in the second half and she crossed the line in 1:03:03, the second-fastest performance in history.SO CLOSE ??????'s Yomif Kejelcha breaks the half marathon world record at the @MedioMaratonVLC ??