Wimbledon 2016: Serena, Venus in semifinals

London: Serena Williams admits she is shocked to be on the verge of meeting sister Venus in the Wimbledon final seven years after they last slugged it out for a Grand Slam title.

For the first time since 2009, both Serena and Venus have made it to the Wimbledon semifinals and the All England Club is abuzz with nostalgic chatter about the potential for a surprise showdown between the American stars in Saturday's final.

To make the dream match-up become a reality, defending champion Serena must beat Russian world number 50 Elena Vesnina on Thursday, while world number eight Venus plays Australian Open champion Angelique Kerber.

Between 2000 and 2010, Serena and Venus won a combined nine Wimbledon titles and made a total of 14 appearances in the final, with four of those being all-Williams affairs in 2002, 2003, 2008 and 2009.

But, just when it seemed the Williams' duopoly in south-west London would never end, in 2011 Venus was struck down by Sjogren's syndrome, an illness that causes fatigue and joint pain, and Serena's win over her sister at Wimbledon in 2009 remains their last title clash.

Venus refused to contemplate retirement and gradually learned how to manage her illness alongside reviving her stalled career.

Now, at an age when most of her contemporaries had long since called it quits, the 36-year-old has willed herself back into contention for an eighth Grand Slam crown.

It is a renaissance that makes Serena proud, but even the 34-year-old didn't expect to still be in which a chance of contesting the sport's top prizes with her sister at this advanced stage of their careers.

"I'm surprised of the longevity of it. That kind of definitely took me by surprise," Serena said.

"When you're younger and you have a dream and you say it and you believe it, that's one thing. But for it to really happen and to come true, it's just a completely different emotion.

"It means Venus has a lot of perseverance. She's a real fighter. Like I always say, it's super inspiring for me. It's really great.

"With everything she's been through, I think it's built a ton of character in her, and in me just by being around her."

Inspired:

World number one Serena, bidding for a record-equalling 22nd major title and seventh Wimbledon crown, appears to have the easier draw against first-time Grand Slam semi-finalist Vesnina, having won all four of their previous encounters.

But five-time champion Venus, who last won a major at Wimbledon in 2008, has a much tougher task against Kerber.

Kerber defeated Serena to win her maiden Grand Slam crown in Melbourne in January and holds a 3-2 edge in her meetings with Venus.

Venus, the oldest women's Wimbledon semi-finalist since Martina Navratilova in 1994, expects an equally inspired display as the German fourth seed targets a first Wimbledon final.

"Well, clearly it was one of her best days on the court," Venus said of Kerber's win over Serena.

"I imagine that she will try to recreate that. Who wouldn't?"

Kerber, 28, lost her only previous Wimbledon semi-final in 2012, but she enjoyed a victory over Venus at the same venue in the Olympics just weeks later.

"I played against her a lot of tough matches. She's always dangerous on grass, especially here in Wimbledon. She has a lot of confidence right now," Kerber said.

"But I'm playing like in Australia,really high-class tennis. I will just try to play aggressive."

If Vesnina beats Serena, it would count as one of the all-time great upsets, but the 29-year-old sounds more like an adoring fan than a player who believes she can spring a surprise.

"Nothing can be better than playing against Serena in a semi-final at Wimbledon," she said.

"Serena, I'm admiring her. She's best player in the world. It will be big challenge for me."