At the 2002 World Junior Championships Gebregziabher Gebremariam won the
10,000 metres and finished third in the
5000 metres race. He also won the World Junior Championships in
cross country running. The following year he made his first impact on the international scene by finishing third at the
1st IAAF World Athletics Final and second at the
All-Africa Games. In March 2004 Gebremariam showed that he had fully progressed from the junior ranks by winning two
silver medals at the
World Cross Country Championships, one over the short course and one over the long course; in essence, were it not for his countryman
Kenenisa Bekele, he would be one of only two men ever to have claimed short and long course victories at the same Championships. He was selected for the Ethiopian
Summer Olympic 5000 metres team along with
Kenenisa Bekele and
Dejene Berhanu, where he finished fourth, 0.25 seconds behind bronze medalist
Eliud Kipchoge of Kenya. Gebremariam finished sixth in the 10,000 metres at the
2007 World Championships in
Osaka. In October 2008 he made his debut in the
half marathon, finishing 2nd in the 2008 Bupa
Great North Run behind
Tsegaye Kebede. He won
gold at the
2009 IAAF World Cross Country Championships. Gebremariam began the 2009–10 IAAF cross country season with a win at the opening meeting – the
Oeiras International Cross Country, and also took victory at the
Cross de Atapuerca,
Cross Internacional de Soria and
Cross Internacional de Alcobendas meetings. He finished tenth in the senior race at the
2010 IAAF World Cross Country Championships. Heading out onto the summer
athletics circuit, he ran a course record of 27:42 at the
UAE Healthy Kidney 10K in
Central Park in May, knocking six seconds off
Tadese Tola's record and beating
Peter Kamais to the line. He was victorious at the
Peachtree Road Race in June, just pipping
Peter Kirui at the finish, and then won the
Beach to Beacon 10K in August. He scored his second road win of the month at the
Falmouth Road Race, beating
Wilson Kwambai Chebet just at the finish. Former world junior silver medallist
Matthew Kisorio bested him at the
Philadelphia Half Marathon, however, as the Ethiopian's time of 1:00:25 was ten seconds short of the victor. He won the
2010 New York City Marathon on his debut over the distance with a time of 2:08:14. Among his competitors was
Haile Gebrselassie, who dropped out mid-race and later announced his retirement. Gebremariam had encouraged his compatriot to stay in the race but the veteran responded "I can't, Gebre, you have to go on". He paid his respects to the world record holder after the race, saying "Haile is a good guy, he is king. I have learned so many things from him". He entered the
New York City Half Marathon the following March and was narrowly beaten at the line by
Mo Farah. In April 2011, he finished third in the
2011 Boston Marathon with a time of 2:04:53 hours. This was among the fastest ever times for the marathon, but it was recorded on a downhill circuit. He ran at Boston's first
B.A.A. 10K race in June and finished second behind
Geoffrey Mutai, a finish which he and Mutai repeated at the
Giro di Castelbuono a month later. He returned to defend his title at the
2011 New York City Marathon, but was again beaten by Mutai and ended the race in fourth place. At the
2012 Boston Marathon he faltered in warm temperatures and ended the race in 14th place with a time of 2:22:56 hours. He qualified to represent Ethiopia at the
2012 London Olympics and finished eighth in the
Olympic 10,000 metres final. He was runner-up to
Mo Farah, the winner of the Olympic race, at the
Rock ‘n’ Roll Mardi Gras Half Marathon in February 2013. ==Personal bests==