Images of Colombia's leftist presidential candidate, Gustavo Petro celebrating on stage after voters gave him a historic lead Sunday in the country's first round of presidential elections that will culminate in a runoff in June. With more than 97 percent of votes counted, preliminary results showed 62-year-old Gustavo Petro, a former Bogota mayor, leading with 40.3 percent to 28 percent for Rodolfo Hernandez, a 77-year-old populist outsider in surprise second place. SOUNDBITE