WIMBLEDON, England — Venus and Serena Williams won in contrasting fashion today to set up their fourth all-sister Wimbledon final and eighth meeting in a Grand Slam title match.

Two-time champion Serena saved a match point and overcame Elena Dementieva 6-7 (4), 7-5, 8-6 in 2 hours, 49 minutes. Five-time winner Venus needed only 51 minutes to overwhelm Dinara Safina 6-1, 6-0 and reach her eighth Wimbledon final.

“Oh my God, this is my eighth final, and it’s a dream come to true to be here again and have the opportunity to hold the plate up,” Venus said.

The sisters — with 17 Grand Slam titles between them — will face each other Saturday in a Fourth of July final.

“A fourth final — it’s so exciting. It was so hard before my match to watch all that drama,” Venus said, referring to Serena’s semifinal. “It was so difficult. But the hardest part is next to come, to play Serena Williams.”

One Williams or the other has won seven of the past nine championships at the All England Club. Serena beat Venus in the 2002 and ’03 finals here, while Venus came out on top against her younger sister last year.

Venus is bidding to become the first woman since Steffi Graf in 1991-93 to win Wimbledon three years in a row.

There have been seven previous all-Williams championship matches at majors, with Serena holding a 5-2 lead. Overall, the sisters are tied 10-10.

Serena, a two-time Wimbledon champion, was pushed to the limit by the fourth-seeded Russian but raised her game when she needed in one of the most compelling women’s matches at the All England Club in years.

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 and combined with Venus to dominate at the All England Club for the past decade.

The 2-hour, 49-minute classic ended when Dementieva sailed a backhand wide, Serena threw her head back, pumped her arms and hopped up and down in celebration.

“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.”

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

Serena and Dementieva had both sailed through the tournament without dropping a set or facing a stern test. On this day, they traded wicked groundstrokes, big serves and brought tense drama to Centre Court.

Serena served 20 aces and had 45 winners and 28 unforced errors. Dementieva produced 27 winners, 26 errors and eight double faults.

Serena, accustomed to starting fast and seizing command early, found herself having to rally from a set down.

It was Serena, surprisingly, who wilted in the tiebreaker, committing two unforced forehand errors to give the Russian a chance to serve for the set at 6-4. Dementieva double-faulted on the first set point, but converted on the second when Serena hit a forehand return wide and nearly spiked her racket to the turf in anger.

Dementieva was up a break at 3-1 in the third, but Serena kept fighting and broke back for 3-2. When Serena fell behind 30-40 on serve in the 10th game, it was Dementieva’s chance to win the match. In a seven-stroke rally, Dementieva tried to pass Serena at the net but the American came through with the backhand volley to stay alive.