The 19-year-old Ghebreslassie crossed the line after 2:12:27 ahead of Ethiopia's Yemane Tsegay 2:13:07 and Munyo Solomon Mutai of Uganda who finished after 2:13:29.
Pre-race favorites current world record holder Dennis Kimeto and former world record holder Wilson Kipsang were among the 25 marathoners that did not finish the race.
Ghebreslassie also became the first Eritrean to win gold medal at world championships.
See full marathon results here>>
Watch last part of the marathon race here>>