2012 — Serena Williams beats Maria Sharapova 6-0, 6-1 to join Steffi Graf as the only women to complete the Golden Slam — winning the Olympics and the four majors. In a men’s semifinal match, Roger Federer outlasts Juan Martin del Potro in a 19-17 final set and clinches his first Olympic singles medal. Canadian equestrian Ian Millar rides into Olympic history by competing in his 10th games — the most of any athlete.

United States’ Serena Williams celebrates after defeating Maria Sharapova of Russia to win the women’s singles gold medal match at the All England Lawn Tennis Club at Wimbledon, in London, at the 2012 Summer Olympics, Saturday, Aug. 4, 2012. (AP Photo/Victor R. Caivano)