Although the drug disqualification of sprinter Ben Johnson was the biggest story of the 1988 Olympics, the Seoul Games were highlighted by numerous exceptional performances. Christa Luding-Rothenburger, who was also a speed skater, earned a silver medal in cycling to become the only person in history to win Winter and Summer medals in the same year. Steffi Graf concluded her Grand Slam tennis season by winning Olympic gold. Greg Louganis repeated victories in both diving events. Florence Griffith-Joyner dominated the sprints. For the first time, all the medalists in dressage were women.