– In less than a month’s time, the stately and genteel All England club has been transformed into a welcoming Olympic locale for the masses, where the world’s best tennis players are wearing colorful clothes and babies can be heard crying in the stands.

But some things don’t change at Centre Court no matter how you decorate the venerable venue. Roger Federer and Serena Williams have both picked up right where they left off at Wimbledon four weeks ago.

One day after Williams won her fifth Wimbledon title, Federer picked up his seventh last month. This weekend, each will try to win Olympic gold for the first time in the Summer Games singles tournament.

”For whatever reason, I'm really relaxed,” said Williams, who has steamrolled her way through the singles tournament, “and I'm just enjoying myself. . . . I just feel like something about this tournament is just making me play well.”

Williams takes the court Saturday against Russia’s Maria Sharapova, and Federer will square off against Britain’s Andy Murray on Sunday in a rematch of last month’s Wimbledon final.

Federer can use the extra day of rest. In a memorable semifinal Friday, he outlasted Argentina’s Juan Martin del Potro in the longest tennis match in Olympic history. It clocked in at 4 hours 26 minutes and required 36 games in the decisive set.

At the conclusion of the marathon third set, del Potro’s desperate backhand hit the net, giving Federer a 3-6, 7-6 (7-5), 19-17 win. That final set alone lasted 2 hours 43 minutes and featured a series of remarkable shots by both players. In the end, Federer secured Switzerland’s first medal of these Olympics.

No, it’s not a Grand Slam event, but Federer said the epic match certainly felt like one.

“You have to hopefully save something for Sunday. You can’t go overly crazy,” Federer said. “But I was very, very touched at the end.”

The match began just past noon in London and lasted until nearly 5 p.m. No one in the packed crowd — Bill Gates and Kobe Bryant among them — seemed to mind waiting for what was supposed to be the day’s main event between Novak Djokovic and Britain's Murray. With a raucous and partisan crowd behind him, Murray later topped Djokovic, 7-5, 7-5, and will now get a chance to redeem his Wimbledon loss from last month.

Federer lost in the quarterfinals at the 2008 Games, and his lone Olympic medal was a gold earned playing doubles in Beijing. Now in his fourth Olympics, he’s made no secret about his desire to add a singles gold to his tennis résumé. Regardless of what happens Sunday, he won’t soon forget his path to the final match.

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

After waiting all afternoon for Centre Court to become free, Williams dominated the world’s top-ranked player, Belarus’s Victoria Azarenka, 6-1, 6-2. In five singles matches this week, Williams hasn’t lost a set and said even she was surprised at how quickly she disposed of Azarenka.

“I kind of was blind today. I didn’t even know where I was going,” Williams said. “But you're playing the best player in the world. You’ve got to play well.”

She’s playing more relaxed than last month’s Wimbledon, she said, because the stakes here feel different than a Grand Slam event. Though Williams has won virtually everything on the tennis landscape except an Olympic gold for singles play, she’s apparently at peace entering Saturday's final.

“Whether I win or lose, that’s not the big deal,” she said. “The big deal for me is USA is guaranteed [a medal]. . . . With me, it's never enough. So this is cool to have a little more, little extra. I'm excited. I like a lot of gravy on my chicken.”

Williams actually has a chance at two gold medals in London. After Saturday’s gold medal match, Williams will return to the court to team with her sister, Venus, in the women’s doubles tournament. The two must get past Russia’s Maria Kirilenko and Nadia Petrova in the semifinals for a spot in Sunday’s gold medal match against the Czech duo Andrea Hlavackova and Lucie Hradecka.

The Williams sisters won gold in Olympic doubles in the 2000 Games and again in 2008.

Bob and Mike Bryan, twins from California, will play in the men’s doubles gold medal match after topping the France’s Julien Benneteau and Richard Gasquet, 6-4, 6-4, Friday. The Bryans won bronze in Beijing four years ago and will be aiming for their first Olympic gold, facing France’s Jo-Wilfried Tsonga and Michael Llodra.