LONDON: A Champagne cork popped somewhere on Centre Court four games into Serena Williams's Wimbledon semi-final and while it was a tad premature, her 6-2 6-0 thrashing of Elena Vesnina suggested she could celebrating something special come Saturday.

The top-seeded American will be taking nothing for granted, having seen her bid to match Steffi Graf's modern era record of grand slam titles stuck one short on 21 for a year, but it was a menacing show of strength, albeit against an overawed opponent.

She dropped only three points on serve in an embarrassingly one-sided 49 minutes -- crunching down one 123mph delivery that topped the women's speed charts at this year's tournament.

Vesnina, the first unseeded woman to reach the semi-finals at Wimbledon since Sabine Lisicki in 2011, had served the second-most aces, after Serena, coming in to the match.

She managed four on Thursday, but it was futile.

"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 commentator John McEnroe's blunt assessment.

Vesnina, who will rise into the world's top 25 having been down at 122 in February, walked off smiling and made no excuses.

"I went in there with a game plan," she said. "But today it was all about Serena."