South African sprinter Oscar Pistorius entered the history books Saturday at the London Olympics. He became the first double-amputee runner ever to compete in the Olympic games.

He came in second in a 400-meter preliminary heat in 45.44 seconds, qualifying him for the semi-finals.

Pistorius was born without fibulas – the outer bones in the lower leg. He wears special prosthetics from just below the knees.

American swimmer Michael Phelps, already the most decorated Olympian of all time with 21 medals, seeks medal 22 Saturday in the men's 4 by 100 medley relay. The race will be the last of his Olympic career.

U.S. tennis star Serena Williams and Russian Maria Sharapova face off in the women's gold medal match.

Jamaican sprinter Usain Bolt makes his debut on Day 8 of the Olympics in a 100-meter preliminary round. Bolt holds the world record in the event.