Image source, Reuters

What a start for Laura Siegemund!

The 37-year-old German makes it clear immediately to top seed Aryna Sabalenka that she's in for a tough game.

She uses drop shot to great effect and although Sabalenka is able to save one break point with a big serve down the T, Siegemund earns another with a marvellous cross-court passing shot.

That's followed up with a backhand winner, again cross-court, to give the Siegemund the early advantage.

Karen Khachanov dropped his opening service game in the first set and finds himself in danger again at the start of the second, some unforced errors gifting Taylor Fritz two break points...

Gary Rose
BBC Sport at Wimbledon

There were plenty of Americans wandering around the outside of Court One when I headed over here earlier and those that were fortunate enough to get a ticket to watch the action are being treat to an impressive display so far by Taylor Fritz.

On this showing he's in no mood for hanging about on the court anywhere near as long as he had in any of his previous full matches at this year's Wimbledon.

At the moment, it is hard to see how Karen Khachanov gets through Fritz's serve.

Taylor Fritz gives away the first point with an unforced error but it's plain sailing from there for the fifth seed, the highlight being a drilled backhand that clips the tramline on its way for a winner.

33 minutes played and Fritz is a set to the good.

Image source, EPA

Taylor Fritz was joined in the last eight by Ben Shelton yesterday, making this the second consecutive year that multiple American players have reached the men's quarter-finals at Wimbledon. Fritz and Tommy Paul did so last year.

Prior to 2024, the most recent time that multiple American men reached the quarter-finals at Wimbledon had been in 2000, when Andre Agassi, Jan-Michael Gambill and eventual champion Pete Sampras got to the last eight.

It is also a fifth consecutive Grand Slam tournament with multiple American players in the men's singles quarter-finals and it is the longest streak of Grand Slam events with multiple American men in the quarter-finals since the 1990s.

Back to the action on Court One, where Karen Khachanov volleys a winner at the net to wrap up a service hold and ensure that Fritz will need to serve out the set himself.

End of the warm-up. They're ready to go on Centre Court.

Aryna Sabalenka to serve first.

It was already a tough first-round task for Britain's Gordon Reid in the men's wheelchair singles coming up against the 2021 champion Joachim Gerard, and it has just become a bit more difficult.

The 2016 winner was broken in the 11th game of the opening set and could not get the break back he needed to take it to a tie-break.

All to do for Reid now as he goes a set down to Belgium's Gerard.

Image source, PA Media

Good, confident stuff from Taylor Fritz, who moves within one game of the first set.

Karen Khachanov just hasn't had a sniff on the American's serve yet - Fritz has got 79% of first serves in and won 16 of the 19 points on his serve so far in this match.

Todd Woodbridge
Former Wimbledon doubles champion on BBC One

Fritz has such a good return. He stands a lot further back from the baseline than players usually do.

You need to have peripheral vision and the ability to keep your eye on the ball and still be aware of what is going on on the other side of the court. Fritz has it, I'm not sure Khachanov does.

Rapturous applause from the Centre Court crowd as Aryna Sabalenka and Laura Siegemund make their way onto the hallowed grass.

Sabalenka wins the toss and elects to serve first.

The return game of Taylor Fritz is looking in decent order at the moment.

He takes Karen Khachanov to deuce and almost gets an impossible pickup of a smash back into play, before Khachanov rounds things off with an ace.

Amy Lofthouse
BBC Sport at Wimbledon

Laura Siegemund is a WTA Tour veteran - but before this year, she'd never gone beyond the second round of the Wimbledon singles.

A brilliant doubles player, she has the type of craft and touch on the court that can drive players not unlike Aryna Sabalenka to distraction.

Asked about her on-court habits in her presser this week, Siegemund said she just quite simply has "weird stuff going on" when she's on court.

"I've been doing it all my life. I was always slow, talking about time violations and stuff," she said.

"That's nothing that just got invented now, you know. I'm pretty consistent with my weirdness that I have."

Gary Rose
BBC Sport at Wimbledon

As expected, the Taylor Fritz serve is proving a powerful weapon, winning points on 92% of his first serves, with Karen Khachanov managing just 43% in comparison.

Fritz has already hit four aces in five games so far and is looking very comfortable.

Todd Woodbridge
Former Wimbledon doubles champion on BBC Two

Fritz does not have as big a forehand as the likes of Alcaraz, but he is already creating a lot of damage here.

Fritz looks good and fresh. His legs should have recovered from his previous big games. Getting a 4-1 lead means you are feeling good. Fritz likes this court too, he has won a number of matches here already.

Top seed Aryna Sabalenka was given a real test by Emma Raducanu in the fourth round but still came through in straight sets.

The 27-year-old is yet to drop a set at this year's Championships as she continues her bid for a first title on grass.

Sabalenka has reached the semi-finals on her last two visits to Wimbledon, most recently in 2023, and after losing in the finals of the first two Grand Slams of the year, will be determined to go one better at SW19.

Standing in her way is Laura Siegemund, who is competing in just her second major quarter-final - five years on from her first at Roland Garros.

The 37-year-old German is also yet to drop a set en route to the last eight, beating Peyton Stearns, Leylah Fernandez, Australian Open champion Madison Keys and most recently Solana Sierra to get to this stage.

If Siegemund can pull off another surprise win today, it would have to go down as the biggest shock of the lot.

BBC Two

Taylor Fritz holds serve in double-quick time, again wrapping it up with an ace, to move 4-1 up.

Live coverage of this match is currently on BBC Two.

John McEnroe
Three-time Wimbledon singles champion on BBC Radio 5 Live's '6-Love-6'

Taylor Fritz himself asked John on Monday what trait he should look to improve the most in his game - except his volleys!

When he hits a big groundstroke, he should be ready to move forward. He has great groundstrokes on both sides but he hesitates.

The other thing is hitting his spots a little bit better on his second serve. His first serves are huge, but he just spins it in on his second serve at times.

Karen Khachanov gets 40-0 up and despite a couple of points going the way of his American opponent, an unreturnable serve down the T seals his first game of the match.

The Russian still trails by a break in the opening set.

Jess Anderson
BBC Sport at Wimbledon

Being out here has made me wonder who the Centre Court crowd will favour today.

Carlos Alcaraz is certainly the star of the show here at SW19. But Cam Norrie is the home player.

It could be interesting to see who will get the big backing.

Todd Woodbridge
Former Wimbledon doubles champion on BBC Two

This is a brilliant start for Fritz. Everything is coming out the middle of the strings and he is dictating the pressure back onto Khachanov.

What's impressive is his directional serving and the quality of it. 122 mph [serve] looks like a walk in the park for him.