 He won the 2009 ITU Triathlon World Championship, winning all five of the season's ITU World Championship Series events in which he competed.He was victorious in Madrid, Washington D.C, Kitzbühel and London before winning the 2009 season Grand Final, held on Australia's Gold Coast on 12 September and thereby became the first person ever to win the ITU world Triathlon titles for Junior Men (2006), Under 23 Men (2008) and Senior Men (2009).During the 2010 off season, Brownlee sustained a stress fracture of the femur and was not able to return to competition until June, which made defence of his ITU title almost impossible.