Twice winner Serena Williams reached the Wimbledon final for the fourth time and third against sister Venus on Thursday with a 6-2, 7-6 victory over Chinese wildcard Zheng Jie on Centre Court.
Serena, who had won their only previous meeting in the first round here in 2004, won the first set in 28 minutes after a first break of serve in the opening game and a 37-minute rain delay with the score 5-2.
Zheng, 24, made a dramatic improvement in the second set which reached 5-5, after an exchange of breaks in mid-set and the Chinese leading 40-30 on her serve when there was a second rain delay lasting 82 minutes.
The set went into a tiebreak after Serena saved a break point in the 12th game. Serena set up match point with a thundering delivery then took it when Zheng double faulted.
Venus Williams, champion four times, reached her seventh final with a 6-1, 7-6 win over Russian Elena Dementieva in the first semi-final.
A big difference between the players was the powerful Serena serve which allowed Zheng, the first Chinese and first wildcard to reach the semi-finals, only three points in the American's first six service games.
In the sixth game of the second set, the Chinese earned one break point which she won with a brilliant low return across court to move 4-2 ahead.
Serena broke right back, pushing the 133rd-ranked opponent to 0-40 then taking the point when Zheng hit the American's return into the net.
Seeming to play almost on tip-toes to make up for her height handicap and exquisitely balanced when she made shots on the run, the 1.65-metre tall Zheng moved Serena about the court with her rasping drives and two-fisted backhands.
The excitement returned at once after the second rain delay with Zheng's service going to deuce six times and her saving two break points before taking a 6-5 lead which helped her reach the tiebreak.
However, the 26-year-old Serena showed all her power in the tiebreak, including three aces, and soon reached match point at 6-5. Zheng's resistance ended when she double faulted, bringing down the curtain on a match that lasted one hour and 25 minutes but took 3:24 to conclude.
"I was ready to go three sets but I felt I didn't want to so I got in some big serves," Serena said.
"I'm happy to be back in a grand slam final, I love it."
Asked if she and her sister would discuss Saturday's final, she added: "(Venus) is a tough opponent, the toughest I've played here (but) we're going to stop talking to each other until the final."