SOBRIETY returned to Wimbledon on Tuesday after the heady brew of the night before with Center Court open to the sunny skies and the Williams sisters blasting through to the semi-finals.

Venus Williams, 29, romped to a 6-1, 6-2 defeat of Pole Agnieszka Radwanska and then Serena powered past Victoria Azarenka of Belarus 6-2, 6-3.

“That first set for me was really almost perfect,” Venus, who is chasing a hat trick of singles title here and her sixth overall, told reporters of her match against former Wimbledon junior champion Radwanska on Court One.

“Do I feel invincible? I’d like to say yes, but I really do work at it.”

Asked if she and Serena were now head and shoulders above the rest, Venus did not exactly dismiss the suggestion.

“I think we are definitely the frontrunners in tennis as far as being some of the best players out there,” she said. “But if there were just two players, it would just be a final. There’s got to be 128. So that’s the way it’s got to be.”

At least Elena Dementieva, the graceful Russian fourth seed, is doing her best to keep up with the Americans.

The 27-year-old performed a Williams-type demolition job on diminutive Italian Francesca Schiavone, winning 6-2, 6-2 on Court One.

Serena refuted a suggestion that fans were being short-changed by one-sided women’s matches but said maybe they should play best of five sets — a scenario that would strike fear into most who face them across the net.

“Yeah, I’m ready for five-set matches. On grass it would be fine. I can definitely play five sets,” she said.

World No. 1 Dinara Safina and unseeded German Sabine Lisicki did provide a contest worthy of the name with the Muscovite wearing down her opponent 6-7, 6-4, 6-1 on Center Court.

“I was tough mentally,” Safina said. “That was the key today.”

In their only other meeting, Lisicki beat Safina in the first round of the 2008 Australian Open.

“Back then was the first round. Now it’s the second week,” Lisicki said. “I think she just knew how to handle it physically better than me.”

Safina now stands between Venus and an eighth Wimbledon singles final when they meet for the first time on a grasscourt in the last four.

“Definitely this is her best surface,” Safina, who is still without a Grand Slam title, told reporters. “She loves playing here in Wimbledon. I know her weapons. I have my weapons. So I just want to go out there, play my best, and let’s see.”

(SD-Agencies)