Defending champion Venus Williams insists she will not lack motivation when she meets younger sister Serena in the women's singles final at Wimbledon on American Independence Day on Saturday.

Their victories over Dinara Safina and Elena Dementieva will ensure the Venus Rosewater Dish will take up residence in the Williams ranch for the eighth time in the last 10 years but Venus insists that will not dull their competitive edge.

"It is different because I'm happy for her to be in the final but I have to face her and defeat her," she said. "I don't necessarily want her to lose but for sure I want me to win."

She added: "Maybe that doesn't make sense but, when I'm playing someone else, for sure I want them to lose.

"I don't like to ever see her disappointed in any way. But at the same time, I don't want to see myself disappointed. I need to get my titles, too.

"I definitely wanted to play against her because the dream has come true for both of us and for our family."

The pair's progress into Saturday's final could hardly have been more different, Serena overcoming Dementieva in the longest women's semi-final in Wimbledon history and Venus blitzing Dinara Safina in the second shortest.

Serena dropped her first set of the Championships and saved a match point before squeezing through 6-7 (4-7) 7-5 8-6 in an epic duel against an inspired Dementieva that lasted 11 minutes short of three hours.

The only previous semi-final to have stretched past two-and-a-half hours was the 1994 battle between Conchita Martinez and Lori McNeil, which lasted 14 minutes shorter.

"I guess I'm always trying to do something to make history, so here I go again," said Serena.