Serena Williams became only the second woman to complete a career golden slam, winning the most lopsided women's final in Olympic history by beating Maria Sharapova 6-0 6-1.
The victory completed a remarkable run of domination by the No.4-seeded Williams, who lost only 17 games in six matches en route to her first singles gold medal. She went 13-0 this summer at the All England Club, where she won her fifth Wimbledon title on the same court a month ago.
"I was so focused here," said Williams. "I remember I was serving and I was thinking: 'Serena, this is your best chance to win a gold medal. You're at Wimbledon, you're on grass, you play great on grass, pull it together, just win this'."
The career golden slam was first achieved by Steffi Graf, who did it when she won at the Olympics in 1988 after sweeping all four major titles. Williams can add the gold medal to her 14 grand slam singles championships, the most of any active woman.
It took the No.3-seeded Sharapova 45 minutes to win a game, and by then she trailed 6-0 3-0. Williams dominated with her serve and repeatedly blasted winners from the baseline taking a big swing with almost every stroke despite gusty conditions.
The wind was so strong it blew the US flag off its pole during the medal ceremony.
Williams finished with 10 aces, 24 winners and only seven unforced errors.
"She's playing incredibly confident tennis," Sharapova said. "Her shots were very powerful."
Sharapova completed a career grand Slam in June by winning the French Open, but Williams beat her for the eighth consecutive time. The most one-sided previous Olympic women's final was in 1920, when France's Suzanne Lenglen beat Dorothy Holman of Great Britain, 6-3 6-0.
Top-seeded Victoria Azarenka of Belarus won the bronze by beating No. 14-seeded Maria Kirilenko of Russia 6-3 6-4. Sharapova's loss allowed Azarenka to retain the world No. ranking.
Roger Federer was to try to complete a career golden slam when he played Andy Murray of Britain in the men's final on Sunday.