“It’s definitely one of my more dramatic victories, for sure,” Serena said.

Dementieva, who has never won a Grand Slam title, played one of the best matches of her career and nearly eliminated a player who has won 10 majors.

After Dementieva sailed a backhand wide to end the match, Serena threw her head back, pumped her arms and hopped up and down.

“Elena played so well, and we gave the crowd a wonderful match,” Serena said. “It was really, really tough.”

In the 10th game of the final set, Serena faced match point on her serve with Dementieva ahead 5-4. Serena chose to attack, coming forward and hitting a backhand volley that skipped off the net cord and into the open court for a winner.

“I thought ace,” Serena said. “It’s my serve, if I can just stay calm. I was just trying to think positive.”

Dementieva said: “The only regret I have, maybe I should take a little bit more risk on match point, should go down the line.”

It was Serena’s eighth straight win in a Grand Slam semifinal going back to the 2003 French Open. She is 14-2 overall in Grand Slam semifinals.

It was almost too much to handle for Serena’s father, Richard Williams, who watched with other family members and friends in the guest box.

“Serena did it the hard way,” Richard said. “This is the first time I ever got nervous at a tennis match. I’ve never gotten nervous before. Serena played the way she practiced this morning. She practiced bad and she played bad. But she’s just so mentally tough that she did it ’The Williams Way.’ She hates losing.”

Serena served 20 aces — the most for a woman at Wimbledon since 2000 — and had 45 winners and 28 unforced errors. Dementieva produced 27 winners, 26 errors and eight double-faults.

“That was the best match we ever played against each other,” Dementieva said. “It was a real fight from the beginning until the end. I feel like I finally played some good tennis here. It was not easy to fight against her. She’s a great champion. She was serving very well today. I wasn’t sure if it’s Serena or Andy Roddick on the other side.”

The men’s semifinals are Friday, with two-time finalist Roddick playing Andy Murray and five-time champion Roger Federer facing Germany’s Tommy Haas. Federer is closing in on a record 15th Grand Slam championship, while Murray is seeking to become the first British men’s winner in 73 years.