sentences:  At the event, Yelena Isinbayeva cleared a world record 4.91 m in the pole vault.Liu Xiang won the men's 110 metres hurdles with a world record-equalling time of 12.91 seconds, defying traditional beliefs about the physical calibre of Chinese (and Asian) sprint athletes.Hicham El Guerrouj capped off his prominent international career with two gold medals in the 1500 m and 5000 m. The Olympic competition in Athens was marred by an incident involving Greek Olympic medallists Konstantinos Kenteris and Ekaterini Thanou, who were alleged to have staged a motorcycle crash in order to avoid doping tests.