The following year, he became the first Ethiopian to win the Dream Mile and he further improved his national mark in the process, running 3:48.95 minutes.[6] He also improved his 1500 m best to 3:32.18 minutes at the Herculis meeting in Monaco.[7] He entered the 2009 World Championships in Athletics in Berlin and reached the 1500 m final. He won the silver medal behind Yusuf Saad Kamel, becoming Ethiopia's first medallist in the event at the World Championships.[8] He competed in both the 1500 m and 3000 m at the season-closer 2009 IAAF World Athletics Final, but failed to medal in either event.[7]
His focus of the 2010 season was to retain his world title at the 2010 IAAF World Indoor Championships. In the buildup to the competition, he ran at the Aviva Indoor Grand Prix in Birmingham and improved his 1500 m indoor best to 3:33.10 – fifth on the all-time rankings.[9] At the World Indoor Championships Mekonnen held off a challenge from Abdalaati Iguider and became the first athlete since Hicham El Guerrouj to win back-to-back 1500 m titles indoors.[10] A stomach problem side-lined him for six months but on his return in January 2011 he broke Bernard Lagat's six-year-long win streak in the Wanamaker Mile at the Millrose Games.[11]