Peru’s original field of 13 Olympic contenders is now down to one athlete: marathon runner Constantino Leon. Leon will compete Saturday, August 23, starting at 6:30 p.m. (Beijing time), in the Men’s Marathon. For fans in Peru, that translates to Sunday, August 24, starting at 7:30 a.m. Thus far, no athletes representing Peru have won a medal in the 2008 Beijing Olympic Games. Constantino became Peru’s last Olympic contender after taekwondo athlete Peter Lopez failed to secure the bronze in the Men’s 68 kg. competition on Thursday, August 21. Lopez was victorious in his first two matches on Thursday, beating Australia’s Burak Hasan 3-1 in the preliminaries and Nigeria’s Isah Adam Mohammad…