WIMBLEDON, England >> Serena Williams says she finds the Olympics at Wimbledon relaxing because of the festive atmosphere, and her matches have certainly been nothing to tense up about.

Williams won another blowout Friday, this time against the world’s No. 1-ranked player, beating Victoria Azarenka 6-1, 6-2. Williams clinched the first singles medal of her career, and she’ll play first-time Olympian Maria Sharapova in the final Saturday.

“I’m just enjoying myself,” Williams said. “It’s just a great vibe to have the USA fans and all the other countries’ fans that come out and root really, really hard. It’s an unbelievable experience.”

In the men’s competition, Switzerland’s Roger Federer played for 4 hours, 26 minutes to beat Juan Martin del Potro of Argentina 3-6, 7-6 (5), 19-17. It was the longest three-set men’s match of the Open era.

“I definitely got a sense that it was something special,” the top-seeded Federer said. “The deeper we went into the match, the more I thought, ‘Wow, this is so cool to be part of a match like this.'”

Federer converted only two of 13 break-point chances, the second coming in the next-to-last game, and had several nervous moments. But he held serve 12 times in the final set to stay in the match.

With the comeback victory, the four-time Olympian is assured of at least a silver. On Sunday he’ll play in the final against the winner of the second semifinal between No. 2-seeded Novak Djokovic of Serbia and No. 3 Andy Murray of Britain.

Through five rounds, the No. 4-seeded Williams has lost only 16 games. She had 16 aces against Azarenka and just five unforced errors to beat a player ranked No. 1 for the 14th time.

“When you’re playing the best player in the world, you’ve got to play well,” Williams said. “I felt like I had nothing to lose — just going for it.”

Sharapova, seeded No. 3, won an all-Russian semifinal against No. 14 Maria Kirilenko, 6-2, 6-3. Sharapova had a 35-7 advantage in winners but still had to rally in the second set, sweeping the final four games.

“Obviously it’s tough to play a Russian on the other side of the net, but I’m happy that one of us can go for gold,” Sharapova said. “It’s incredible, not only to be a part of this event and be an Olympian, but to put yourself in with an opportunity to go for gold. It’s a really nice feeling.”

Williams or Sharapova will become just the second woman to complete a career golden Grand Slam, something achieved only by Steffi Graf, who did it by winning the Olympics in 1988.

Sharapova has won each major title once and completed a career Grand Slam by winning the French Open in June.

“Baby steps, I guess,” Sharapova said. “It’s been amazing to achieve what I have achieved. Obviously growing up you have big dreams and hopes of winning your certain favorite tournaments. I’ve been fortunate to win all the Grand Slams, and obviously this is my first Olympics, so I’m just thrilled to be in the final.”

If Sharapova wins, she’ll regain the No. 1 ranking from Azarenka.

Williams has won 14 Grand Slam singles championships, the most of any active woman, including her fifth Wimbledon title a month ago. But this week has been different from Wimbledon, she said.

“I’m way more relaxed this time around,” she said. “Something about this tournament is just making me play well, maybe because it’s not what I worked for my whole life, like to get a Grand Slam. I’m not, like, stressed out — ‘This could be it, No. 14 or No. 15.’ I feel like whether I get a medal or not, I’m happy.”

Williams seeks her third gold medal. She teamed with her sister Venus to win the gold in doubles in 2000 and 2008. They play in the semifinals Saturday.

In doubles, Americans Bob and Mike Bryan are assured of at least a silver after beating Julien Benneteau and Richard Gasquet of France 6-4, 6-4 in the semifinals. Mike Bryan and Lisa Raymond advanced to the first Olympics mixed doubles final since 1924 by beating Del Potro and Gisela Dulko 6-2, 7-5.