In London on 22 April 2007, Haile challenged the 2006 London Marathon winner Felix Limo, 2005 London Marathon winner Martin Lel, 2004 Athens gold medalist Stefano Baldini, 2006 New York Marathon winner Marílson Gomes dos Santos, and the then marathon world record holder Paul Tergat in what organizers anticipated would be an exciting race. However Haile dropped out at the 18-mile (29 km) stage complaining of a stitch and inability to breathe, which turned out to be an allergic reaction to the pollen in the air. This left the 2005 winner Martin Lel to come home in first place.
One month later, Haile made a surprise return to the track for the first of two stadium races that summer. In the first, he ran a 26:52.81 in finishing fifth in a very competitive 10,000 metres race in Hengelo, The Netherlands. It was the first time a man over 30 ran the 10,000 m in less than 27 minutes. Then, on 27 June 2007, Haile launched an attack upon the world record for the one hour run, in Ostrava, Czech Republic. This record attempt was successful as Haile passed the hour mark at 21,285 metres (13 miles 397 yards), eclipsing the previous best of 21,101 metres, set by Mexican Arturo Barrios in La Flèche, France, on 30 March 1991. Furthermore, Haile covered 50 laps (20,000 m) in 56:25.98, another world best, well within the previous 56:55.6 also set by Barrios in 1991. These were his 23rd and 24th world records.
Haile made his running debut in New York City when he won the New York City Half Marathon on 5 August 2007, in 59:24, breaking the previous course record by two minutes. His win in the Lisbon Half Marathon (59:15) in March 2008 gave him a perfect record of 9–0 in winning all of his half marathons. He lost his first half marathon in Den Haag (14 March 2009), when he was beaten by Sammy Kitwara (59:47 for Kitwara, 59:50 for Haile)
On 30 September 2007, Haile won the Berlin Marathon in 2:04:26 (4:44.8 per mile), setting the world record and shaving 29 seconds off Paul Tergat's record, set on the same course in 2003. His victory further energized the celebrations of the Ethiopian Millennium (unique to the Ethiopian calendar), which began on 12 September 2007.