He scored a striking victory at the 2006 IAAF World Road Running Championships in Debrecen, Hungary, finishing the 20 km race in 56:01 – a time which was second only to Haile Gebrselassie's world record and was forty seconds faster than the silver medallist Robert Kipchumba. It was first time that an Eritrean had won a major world title in sport. As Zersenay did not possess a strong sprint finish (crucial for success on the track) commentators suggested that a move to the marathon distance seemed an obvious career progression, but he downplayed the idea, stating that he would not change distances in the near future. He closed the season with a run at the New Year's Eve 10 km road race: the San Silvestre Vallecana in Madrid. Zersenay and Eliud Kipchoge were awarded the same time of 26:54, but Kipchoge was announced as the race winner. Although this was faster than Haile Gebrselassie's world record of 27:02 at the time, it was not ratifiable as the runners benefited from the race's downhill circuit.