Defending champion Serena Williams withstood stiff early resistance from unseeded Czech Petra Kvitova before winning 7-6, 6-2 to reach her sixth Wimbledon singles final on Thursday.
Kvitova, the world number 62, had been expected to be little more than a sacrificial lamb on Williams's route to a fourth crown at the All England Club, but the feisty Czech gave as good as she got in a tight first set.
She broke Williams's serve in the fifth game but the American levelled and took the tiebreak 7-5.
Kvitova battled defiantly in the second set but a double fault to hand Williams a double break at 5-2 meant there was no way back.
She will play Russian 21st seed Vera Zvonareva in Saturday's final.
Zvonareva survived an early wobble before scoring a 3-6, 6-3, 6-2 victory over unseeded Bulgarian Tsvetana Pironkova in the other semi-final.
The 21st seed reached her first Grand Slam final after a slow start against the world number 82, losing the first set before coming through with increasing confidence on a cloudy, breezy day on Court One.
"I'm very excited, I'm not realising it at the moment... It's one of my dreams to be out there (in the final)," the 25-year-old said in a courtside interview.