Serena Williams stood just one match away from setting up another family showdown in the Wimbledon final after she hurtled into the last four with a 6-2 6-3 win over Belarussian Victoria Azarenka.
The American was in stupendous form as she produced 25 winners, compared with only seven for her eighth seeded opponent, during the 73-minute exhibition of power tennis on Centre Court.
The U.S. Open and Australian Open champion will next face Olympic champion and fourth seed Elena Dementieva.
However, fans and pundits alike feel that match will only be a formality for the American and she is being tipped to meet sister Venus in Saturday's showpiece match for the second year running at the grasscourt grand slam.
Earlier, third seed Venus stayed resolutely on course for a third successive title with a 6-1 6-2 victory over Poland's Agnieszka Radwanska.
Venus, seeking her sixth career title here, has not lost a set at Wimbledon since the 2007 third round and the 11th seeded Radwanska rarely threatened a shock on a sun-kissed Court One.
"She's such a great grasscourt player, she plays the ball so low and plays so quick. I was happy to get through," Venus said in a courtside interview.
"I can't complain, the semi-finals at Wimbledon is right where I want to be."
At the prospect of a fourth Wimbledon final against sister Serena on Saturday, she said: "That would be fantastic, something I am hoping for, of course."
Venus raced to the first set in 27 minutes and though the Pole broke early for a 2-0 lead in the second, the seven-times grand slam winner reeled off six straight games, clinching victory with a forehand winner after an hour and eight minutes.
Venus will play top seed Dinara Safina, who came from a set down to reach her first Wimbledon semi-final with an unconvincing 6-7 6-4 6-1 victory over Germany's unseeded Sabine Lisicki.
Safina, whose tortured expressions suggest she is as much battling her own game as her opponent's, remained on course for a first career grand slam title despite a flurry of double faults at crucial moments on Centre Court.
The two shared a break of serve each in the opening set which Lisicki clinched 7-5 in a tiebreak when the Russian ballooned a second serve long for her seventh double fault of the set.
She restored order in the second with a single break enough to help her level the match and Safina raced through the third when a Lisicki mishit dropped wide.
In the other half of the draw, Olympic champion Elena Dementieva reached the semi-finals for the second straight year with a crushing 6-2 6-2 victory over unseeded Italian Francesca Schiavone.
The 29-year-old Schiavone had never passed the third round here in eight previous visits and rarely looked like threatening the crisp-hitting of the fourth-seeded Dementieva.
The Russian broke serve three times in the opening set and Schiavone's resistance proved equally ineffective in the second, and Dementieva progressed when the Italian veteran slapped a backhand over the baseline after 66 minutes. She will play second seed Serena Williams of the U.S for a place in Saturday's final.