When Venus Williams stood by her equipment bag, wearing a patriotic navy blue ensemble, and signaled past the purple barrier and up into the stands for the men in bright aqua, it seemed this could not be Wimbledon at all. Williams was in search of pins, Olympic pins she knew men from the Bahamas would have. She wanted to swap, right there on Center Court at the All England Club.

“People are clearly cheering for their nations,” Williams said. “Obviously the Olympics are happening all around us. We’re watching them every day. There’s no confusion about what this is.”

There is no place more hallowed for Williams, nor for tennis as a whole, than the grass on which she easily dispatched Canada’s Aleksandra Wozniak Tuesday afternoon. This may have been the second round of the Olympic tournament, but it is the most familiar ground for the sport’s most luminous stars. Less than a month after Wimbledon closed, Williams and Novak Djokovic and Andy Murray and Maria Sharapova all graced the well-worn grass of Center Court, trying to win an important, yet undeniably different, tournament.

“It’s very special, because I dreamed about the Olympics when I was a kid, and now it comes true,” Frenchman Jo-Wilfried Tsonga said. “And it’s maybe better than my dreams.”

Tsonga can say such things, because he authored the definitive match of the tournament thus far, wearing the blue for France rather than the whites of Wimbledon. He swapped the first two sets with Canada’s Milos Raonic on Court 1. He endured a rain delay. And then they locked in. In Wimbledon, the men’s matches are best-of-five sets, and if they reach a fifth set, there are no tiebreakers. In the Olympics, they play best-of-three, but when they get to a third, there are still no tiebreakers.

So on Tsonga and Raonic went to 10-10, to 15-15, to 20-20, each time Tsonga winning on his serve to take the lead, then Raonic countering with his own booming serve to pull even.

“Point after point, game after game,” Tsonga said, “you don’t think any more.”

The rest of the day’s supposed featured matches went quickly. Williams, Murray, Djokovic and Sharapova all advanced in straight sets. So there had to be something else that showed how meaningful this tournament can be to those who are here. When Tsonga finally broke Raonic in the 48th game of the final set, there it was: 6-3, 3-6, 25-23.

Maybe it wasn’t John Isner over Nicolas Mahut, 70-68, in a Wimbledon fifth set two years ago. But the bellows Tsonga let out afterward, and the way he galloped around the court nearly ripping his shirt from his back, showed he was every bit as satisfied winning the longest three-set Olympic match in history by taking the longest set in Olympic history.

“I’m really happy that there are some good matches in the Olympics like this,” Tsonga said. “It’s good for tennis, and it’s good for sports.”

Though London has hosted the Olympics before, Wimbledon has never hosted the Olympic tournament. “It’s the best tennis venue in the world,” said American Andy Roddick, a three-time Wimbledon finalist. “It’s a no-brainer.”

But there have been some adjustments for the players on their return trip here. The roads around the All England Club are closed, just as so many are in and around London during the Games. The locker rooms have been switched. The crowd is more partisan. The white outfits are replaced by blazing colors. The green backdrops, so understated, are covered by an audacious purple, then emblazoned with the Olympic rings.

“It was always going to be a little weird,” said Roddick, who was thrashed by Djokovic 6-2, 6-1, on Tuesday. “It’s Wimbledon, but it’s kind of not. I said it’s like ‘Olympified Wimbledon.’ It’s different. It’s weird for us, because we have a history at this venue but it’s not quite the same. They’re not the familiar faces working here. You don’t really know anybody by a first-name basis.”

The tennis, though, seems important. Laura Robson of Britain, who pushed third-seeded Sharapova of Russia to a tiebreaker in the first set only to fall, looked positively glum after the result. Asked whether she was disappointed by or proud of her 7-6 (7-5), 6-3 loss, she responded, “What do you think?” Only disappointment graced her face.

“When you’re in this atmosphere,” Sharapova said, “how can you not be motivated?”

Djokovic clearly is. He lost in the semifinals to Roger Federer at Wimbledon, and therefore lost the No. 1 ranking. But he called his performance against Roddick “a perfect match in every sense,” and Roddick would not argue.

“He beat the crap out of me today,” Roddick said.

Djokovic, who has won five Grand Slam titles but only the bronze in the 2008 Olympics, would have been quite pleased with that result in the Wimbledon tournament. But here, as he wore a Serbian t-shirt under a Serbian sweatsuit, he joked about pursuing pictures with athletes — particularly Usain Bolt, whom he has not yet met.

“It’s an incredible experience,” he said.

Williams is in her fourth Olympics, and she and her sister Serena, with whom she advanced in the doubles tournament Tuesday, collected hundreds of pins from fans and athletes around the world. Tuesday, after their victory, Serena Williams became distracted by the same two Bahamian men with whom Venus had exchanged pins at center court.

“Do you have Jamaica?” Serena cooed. “I don’t have Jamaica.” She grabbed the pin-laden lanyard around the man’s neck. “Come, come, come, come.”

She ended up with a pin from Tanzania in exchange for a photo. Never before at Wimbledon. Only at the Olympics. For now, they are one and the same.