The Williams sisters will meet in the Wimbledon final for the third time on Saturday after both played out strikingly similar semi-finals this afternoon. Venus was first to book her place with a two-set win over Russian Elena Dementieva before taking her seat at Centre Court to watch her sister get a fright from China's Zheng Jie.
Serena took the opening set 6-2 but was pushed all the way in the second set and, like Venus, won the match on a tie-break (7-5) when Zheng served her first double fault on the crucial point.
Zheng enjoyed a dramatic run to the semi-finals, including a shock victory over world number one Ana Ivanovic, but the wildcard entrant finally met her match on Centre Court.
Two-time champion Serena broke in the first game of the first set and again for a 4-1 lead, which she consolidated with a comfortable service game.
Although she missed three set points against her opponent's serve in the seventh game, she returned after a 45-minute rain delay to take the set with a love service game.
Zheng performed better at the start of the second set and it was no surprise when she secured her first break of serve to open a 4-2 lead.
However, her nerves returned in her next service game as Serena raced into a 0-40 lead before taking the second of her three break points.
Unseeded Zheng battled to hold serve before forcing a set point as Serena served at 5-6 only to miss her golden chance with a forehand error.
Serena blasted into a 5-2 lead in the breaker, but was pegged back as Zheng won three successive points to level at 5-5.
A big serve, which Zheng unsuccessfully challenged, edged Serena ahead and the match ended in anti-climax when the Chinese player double-faulted at 5-6.
Defending champion Venus, aiming for her fifth Wimbledon title, claimed a 6-1 7-6 victory.
She broke Dementieva's fragile serve twice in the opening three games and the Russian had to save two more break points to finally get on the scoreboard after an 11-minute fifth game.
That was greeted with a loud cheer by a crowd obviously keen to see more of a contest, but Dementieva committed more unforced errors to lose her serve to love and give Williams the set after 38 minutes.
Dementieva was broken again early in the second set but hit back immediately to level at 2-2 and the remainder of the set went with serve, meaning a tie-break was required.
Williams went on to dominate the breaker, winning it 7-3 to move into Saturday's final.