WIMBLEDON, England » Four-time Olympian Venus Williams walked off Wimbledon’s cozy Court 2 gleefully waving her fist as fans chanted, "U-S-A! U-S-A!"

Twenty minutes later, at the other end of the All England Club, Serena Williams departed Court 1 with a triumphant grin and a shout of "Wooo!"

Ten minutes after that, Roger Federer closed out his latest Centre Court victory in pursuit of his first career singles gold medal.

A schedule backlog transformed the Olympics at Wimbledon into a parade of Grand Slam champions Monday, with the Williams sisters and Federer all playing at the same time.

And all won.

"What a good day for fans between me, Venus, Roger and all the other players," Serena Williams said. "It’s really such a great experience."

Venus Williams waited an extra day because of rain to begin her bid for a record fourth gold medal in Olympic tennis, then defeated recent French Open runner-up Sara Errani of Italy 6-3, 6-1.

Serena completed a July sweep of Poland’s Radwanska sisters by beating Urszula in the second round, 6-2, 6-3. Federer also reached the third round, beating Julien Benneteau of France 6-2, 6-2.

After winning in singles, the Williams sisters began a bid for their third Olympic doubles gold by eliminating Sorana Cirstea and Simona Halep of Romania 6-3, 6-2. They won in 2000 and 2008.

Other major champions to advance in singles on a cool, sunny day included three-time Olympian Lleyton Hewitt, top-seeded Victoria Azarenka, Kim Clijsters, Petra Kvitova, Ana Ivanovic and three-time Wimbledon runner-up Andy Roddick.