Wimbledon, London :Defending champion Serena Williams reached her third successive Wimbledon final after seeing off a challenge from the gritty Petra Kvitova 7-6 (7/5), 6-2 on Thursday.
The world number one was given a tough fight by the unseeded Czech world number 62, but Kvitova began to run out of steam in the second set and could not stop Williams from edging towards a fourth Wimbledon title.
"It definitely wasn't easy. I worked really hard," the American top seed said. "I'm happy to still be here, it's such a blessing to still be in the tournament."
Williams now faces Russian 21st seed Vera Zvonareva in Saturday's final.
"Vera is a great player. I've had some unbelievable matches against her," the 28-year-old said.
"It will be tough. I feel like I have nothing to lose going into the final and she doesn't either, so it will be good."
The victory means that at least one of the Williams sisters has advanced to 10 out of 11 straight finals here, with Serena now having made six of them.
Williams is chasing a 13th Grand Slam singles title. She won her three at the All England Club in 2002, 2003 and 2009.
She is yet to drop a set here this year, though Maria Sharapova and Kvitova at least took her to first set tie-breaks.
Kvitova had never won a game on grass before her run here, including two first-round defeats at Wimbledon, and only once before this year had she strung together back-to-back wins.
The Czech number three's previous best Grand Slam result was reaching the 2008 French Open fourth round.
Kvitova, 20, one of the rare left-handers on the women's tour, was the youngest player to reach a Grand Slam semi-final this year.
She was being watched by Czech 1973 Wimbledon champion Jan Kodes and Helena Sukova, who won nine Wimbledon doubles titles. Her parents had also flown in especially for the match.
In their only previous encounter, Williams beat Kvitova in the second round of this year's Australian Open, winning 6-2, 6-1.
But here, Kvitova was aggressive from the start, showing no sign of being intimidated by facing the champion on Centre Court.
She had a break point in the first game, but Williams sent down some unreturnable serves to hold off the early challenge.
The American had a break point herself in the next game but Kvitova dug in to see out the game.
The Czech served a game to love to make it 2-2 and then broke in the next game.
Kvitova was looking to be aggressive on the Williams second serve, and produced a drop shot for the advantage and won the deuce when her opponent hit the net.
Williams had a break point when Kvitova double-faulted, but the Czech player saw it off to lead 4-2.
Williams served the next game to love then had a break point on the deuce, taking it when Kvitova hit the net, making it 4-4.
The next four games went with serve, forcing a tie-break.
Kvitova made unforced errors to go 4-0 down and though she fought off two set points, Serena sent down an unreturnable serve to seal the set.
The first four games of the second set went with serve, including one from each to love.
Williams then had a break point and converted it when Kvitova hit the net.
The Czech took the champion to deuce but Williams held on for a 4-2 lead.
In the next game, Kvitova served a double fault to give Williams a break point, but pulled it back to deuce after a thrilling rally.
She then served another double fault to give Williams the game and leave the American serving for the match.
Williams had three match points and blew two of them, but finally won it through a lucky net cord after an hour and 33 minutes.