Serena Williams was pushed to the limit by Elena Dementieva in a marathon semi-final before squeezing through to Saturday's Wimbledon women's singles final, where she will face her sister Venus, who thrashed the No 1 seed Dinara Safina 6-1, 6-0 in the other semi-final, for the fourth time.
In a tense and enthralling match the two-times champion had to dig deep to win 6-7, 7-5, 8-6 and end the Russian's hopes of reaching her first Wimbledon final.
A gruelling final set tested both players' nerves and stamina to the limit, with Williams surviving a match point in its 10th game and needing to dig deep again to stay in at 6-6. But she broke the No4 seed's serve in the next game and served out to win.
Williams had begun the match in ominous fashion with an ace, her 41st of the Championships, but the Russian produced a crashing forehand to earn a break point and followed it up with a sweet backhand down the line to draw first blood.
However, Dementieva failed to make the most of her flying start, allowing her opponent to break back immediately, and Williams was not threatened again on her serve in the opening set.
Neither player had dropped a set on their way to the last four and the Russian looked certain to be the first to crack. But she demonstrated her self-belief by fighting back from 0-40 in the eighth game to keep the set on serve and produced a love service game to force a tie-break.
Williams put a forehand wide to give Dementieva the first mini break and the Russian pounced on a weak second serve to move into a 6-3 lead. A double fault, the one weakness in Dementieva's game this Wimbledon, threatened to undo the good work but Williams' accuracy on her forehand once more deserted her to hand the tie-break to the Russian with a 7-4 score.
There was no obvious weakness in Dementieva's game. She kept her errors on serve to a minimum, underlined her status as arguably the best returner in the women's game and demonstrated a resolve not to be out-hit in the baseline rallies.
However, doubts began to surface in the opening game of the second set when the accuracy of her groundstrokes deserted her. Williams got the break and duly consolidated but Dementieva came up with a wonderful array of groundstrokes in the sixth game to break the American to love and get the set back on serve.
A 110mph second serve ace by the Russian averted the danger of another break and Williams was forced to dig deep to save two break points and avoid going 5-3 behind. With the finishing sight in line, Dementieva began to show a sign of nerves and Williams achieved a crucial break to edge 6-5 ahead after successfully challenging a call on the sideline.
Serving for the second set, Williams suddenly found herself 15-40 down but was determined not to go out with a fight and came up with more aces to save two of four break points and a 12th ace of the match to secure the set at 7-5.
Dementieva persevered though, and broke early in the deciding set for a 3-1 lead only for Williams to break back immediately as the match continued to twist and turn. Williams looked as if she was beginning to tire and a thumping forehand winner in the 10th game gave Dementieva a break and match point only for Williams to retrieve it with a low volley that clipped the net. The match remained close until Williams secured a break in the 13th game that proved decisive.