Serena Williams will face world number one Victoria Azarenka in the Olympic Games semi-finals after the Wimbledon champion destroyed Caroline Wozniacki's hopes on Court One.
Williams had not lost a set going into today's clash against Wozniacki, and the American looked in supreme form again, humiliating the former world number one in the first set before wrapping up a 6-0 6-3 win.
The American, a two-time Olympic doubles champion with her sister Venus, will be guaranteed her first Olympic medal in the singles if she beats top seed Azarenka tomorrow.
Azarenka had to battle much harder to book her place in the last four as she edged past seventh seed Angelique Kerber from Germany on Court One.
Both players struggled to hold serve throughout - there were 10 breaks during the match - as the Belarus player registered a narrow 6-4 7-5 win.
Azarenka, who lost to Venus in the third round in Beijing four years ago, is refusing to get carried away with her success despite being just one victory away from her first Olympic medal.
"It (winning a medal) still seems really far away," Azarenka said.
"I'm not thinking about it at the moment. I'm just focused on myself and hopefully the result will take care of itself.
"I just have to stay focused now.
"It was definitely a really tough match today.
"We showed very high quality tennis and a lot of fight."