BEIJING -- Double-faults have long been a problem for Elena Dementieva. In the Olympic final, they were her friend.
Taking advantage of 17 double-faults by fellow Russian Dinara Safina, Dementieva won the singles gold medal in women's tennis Sunday at the Olympics, 3-6, 7-5, 6-3.
Dementieva has been plagued for much of her career by a shaky serve, but it was a frustrated Safina who struggled to put the ball in play. After double-faults she flung her racket, banged it against the concrete and smacked a ball into the stands, but the tantrums failed to help.
Dementieva also packed more punch from the baseline and hit twice as many winners, 26 to 13.
In doubles, Venus and Serena Williams of the United States won the gold, beating Anabel Medina Garrigues and Virginia Ruano Pascual of Spain 6-2, 6-0. The sisters celebrated with shrieks, then shared a hug.
When the No. 5-seeded Dementieva closed out her victory with a forehand winner, she collapsed to her knees, then walked to net and received a congratulatory hug from Safina. Dementieva, who won the silver medal at Sydney in 2000, snapped Safina's 15-match winning streak.
"I never expected a medal -- gold, silver or bronze," said Dementieva, 26. "It's unbelievable. For me this is the best moment in my career. I'll never forget it."
Russia swept the medals in women's singles when Vera Zvonareva beat Li Na of China 6-0, 7-5 to win the bronze. That victory made Russia the first nation to win all three medals in one tennis event since Great Britain did so in the 1908 women's singles.
Tennis was not a medal sport between 1924 and 1988.
The Williams sisters improved their lifetime Olympic doubles record to 10-0. They won the doubles gold at Sydney but didn't play in Athens four years ago because Serena was hurt.
"It does mean more for me to win it with Serena, to share this kind of moment with your sister," Venus said. "I mean, we are practically joined at the hip."
Yan Zi and Zheng Jie of China beat Ukraine's Alona and Kateryna Bondarenko for the bronze, 6-2, 6-2.
The singles final began with only about a thousand spectators in the 10,000-seat stadium, but it was mostly full by the end 2½ hours later.
Dementieva lost her first three service games and needed 14 points to hold for a 1-0 lead in the second set, giving her a toehold in the match. A flurry of errors by Safina in the final game of the second set helped Dementieva break to even the match.
Safina said she felt the toll of playing nine matches -- three in doubles -- in the past week.
"I was not the freshest today physically," she said. "To serve, you have to push yourself up, to jump up. And when the legs are a little bit slow, it just doesn't go."
In the final set, Safina broke her racket when she double-faulted three times to lose serve and fall behind 3-1. She served with a chance to reach for 4-all but committed four unforced errors and her final two double-faults.
Dementieva then served out the victory to complete the best week of her career. She beat eight-time Grand Slam champion Serena Williams in the quarterfinals.