A champagne cork popped somewhere on Centre Court four games into Serena Williams' Wimbledon semifinal on Thursday.

While it was a tad premature, her 6-2, 6-0 thrashing of Elena Vesnina suggested she could be celebrating something very special on Saturday.

The top-seeded American will be taking nothing for granted when she plays Angelique Kerber in the final, having seen her bid to match Steffi Graf's modern era record of 22 Grand Slam titles stuck at one short for a year.

But it was a menacing show of strength, albeit against an overawed opponent in Vesnina.

Williams dropped only three points on serve in an embarrassingly one-sided 48 minutes in crunching down a 123-mph serve that topped the women's speed charts at this year's tournament.

From the moment the 34-year-old nonchalantly broke serve in the opening game, the writing was on the wall for a leaden-footed Vesnina, who lasted three minutes less than Dinara Safina did against Venus Williams in the previous shortest women's semifinal in the modern era (2009).

By the time the stragglers got to their seats two games later, Serena was ahead 3-0 and her place in a ninth Wimbledon final was already looking like a done deal.

She will land a seventh Wimbledon title if she beats Germany's fourth seed Kerber in a repeat of this year's Australian Open final that Williams surprisingly lost in three sets.

If any more incentive were needed there is family honor at stake after Kerber beat older sister Venus 6-4, 6-4 in the second semifinal, denying the 36-year-old a first Wimbledon final since 2009, when Serena beat her.

Serena also has the fresh pain of her French Open final loss to Garbine Muguruza, and there was a steely look in her eye when she spoke to reporters afterwards - leaving no doubt that finishing runner-up again is not an option.

"I think for anyone else on this whole planet, it would be a wonderful accomplishment (reaching three Grand Slam finals in a row)," Serena said.

"For me, it's not enough. For me, it's about holding the trophy. But I think that's what makes me different. That's what makes me Serena."

World No 50 Vesnina briefly held up Williams in the first set, holding serve twice, but she managed only five points in the second as the match raced away in a blur of winners from across the net.

Few of Williams' 85 singles wins at the All England Club could have been easier.

"I felt like the score was going fast," said Vesnina, the first unseeded woman to contest a Wimbledon semi since 2011. "I felt like I had no chance today."

While Vesnina, a three-time Grand Slam doubles champion, managed to raise a smile as she walked off, her performance clearly did not impress three-time men's winner John McEnroe, who is now a television commentator.

"Let's be real. I'm guessing it's a combination of fatigue and her freezing. Her legs looked like they weighed 200 pounds each," was McEnroe's blunt assessment.

But as Vesnina pointed out, it was all about Serena - and if she can replicate the form she showed on Thursday, it seems the long-awaited 22nd major title will be her's on Saturday.

"It will be great to see Serena compete for her 22nd Grand Slam title, but you always want more competitive matches," said 1999 champion Lindsay Davenport.

"It has been the tournament of Elena Vesnina's life, but this was a tough day at the office for her."