Annabel Croft
Former British number one at Wimbledon

She's getting frustrated, Osaka. Everything she is throwing at Kerber is coming back. Her best shots are being absorbed and sent back with interest.

She has to hope Kerber drops off and she can step up. She is playing great tennis and the scoreboard is going against her.

Image source, Reuters

Alexander Zverev looks bewildered after a deep Ernests Gulbis shot is called in. The German challenges, and is absolutely right - he makes it two successful challenges in two points after correctly thinking a serve kissed the chalk, just the cheekiest of nibbles.

A third challenge in a row? Nope, Zverev thinks about it and brings a giggle from the few people that are in Court One, but decides not.

No bother, he holds.

Hello.

Two more break points for Angelique Kerber, one courtesy of a sumptuous angled backhand, and she doubles her advantage as Naomi Osaka whizzes a short forehand into the net.

Annabel Croft
Former British number one at Wimbledon

Kerber is really dialed in. Nothing moody about her today that's for certain

Zing! What a passing return from Ernests Gulbis as he finally gets off the mark on the Zverev serve, but it's makes barely a dent in the fourth seed's hold.

Gulbis, who beat British wildcard Jay Clarke in the first round, again has to put in a bit more groundwork to hold his serve after slinging down a pin-point forehand winner.

It remains on serve.

Image source, Reuters

Naomi Osaka is taken to deuce on her serve but she gets herself on the board, and the Japanese angles soem terrific forehand winners to get herself to 15-30.

Angelique Kerber closes out that advantage with a backhand drive, but Osaka forces deuce.

She's left annoyed, though, as she clatters a simple return into the net, and Keber closes out the game to ensure she keeps her nose in front.

Big-serving German Alexander Zverev whistles to an opening love-hold. Ernests Gulbis finds a little more resistance, but holds with an ace that kicks up some white chalk and stays low.

Court One looking pretty sparsely populated at the minute, something else going on?

Image source, Reuters

Absolutely no messing aronud from Angelique Kerber, who backs up her break with a hold to love.

Osaka beat Kerber in the first round of last year's US Open. Kerber arrived as the defending champion, and left having dropped out of the top 10.

Image source, Reuters

Annabel Croft
Former British number one at Wimbledon

Both players will know that section of the draw holds opportunity with Simone Halep's exit, but they can't think about that right now. They need to take it one ball at a time, as boring and cliché as it sounds;

Angelique Kerber conjures up two break points in Naomi Osaka's opening service game.

Osaka saves one but Kerber whacks a backhand out wide and Osaka can't return it cleanly. Break to Kerber.

Over on Court One, it's fourth seed Alexander Zverev against world number 138 Ernests Gulbis.

The 21-year-old Zverev will get this one under way.

And Rafa Nadal keeps on marching on.

He saw off Australia's Alex de Minaur in straight sets on Centre Court this afternoon.

Hseih Su-Wei after beating number one seed Simona Halep:

"This is the first time I have beaten the world number one, it is amazing. On the first set I was there but a little tight, tried a little too hard but happy made it for the second set. It was a lot of support from outside that pushed me and I kept fighting. Thank you so much.

"She played amazing, I had to run and fight for every point. I tried to concentrate on my game and calm down a bit, that helped a lot.

"This year I have tried to enjoy more, not just tennis but life, food, strawberries and cream, lobster. I am really enjoying playing tennis, If I need to hit it big I will, if I feel I need to sit out the point i just do it. I just feel free on the court."

Image source, EPA

Joel: Halep's out now. Does anyone want to win the women's title?

Paul: Hsieh knocks out Halep. 2018 Wimbledon women’s draw continues to throw up surprises

Ayo: At this rate, world number 181, a certain Serena Williams will be the highest seed left in the Wimbledon ladies draw!

Up next on Centre Court: 2016 finalist and 11th seed Angelique Kerber takes on Japan's Naomi Osaka.

Here's the winning moment for Hsieh Su-wei.

She'll face Dominika Cibulkova in the next round - the Slovak has just blasted past Elise Mertens 6-2 6-2.

Karolina Pliskova is the only one of the top 10 women's seeds to make it to the second week.

Image source, Getty Images

Sir Bobby Charlton stuck that one out, rather than disappear for the football. He was treated to an intriguing match, although Rafael Nadal was always in control in the two hour, two minutes on court.

And here is Nadal: "A positive match against a player with a lot of energy, some tough moments."

Asked about playing in front of a Royal Box full of sporting stars: "Playing in front of very important people from sport around the world is always a big honour, we talk the same language and it's great to have all these people.

"I am just happy to be in the fourth round again. I'll go and watch some football - England, it's coming home or not?!"

Tracy Austin
Two-time Grand Slam champion on BBC TV

The crowd on their feet, so much respect for Hseih. The she gave when it looked like she has nothing to give. For Halep a great disappointment, she did have match point.

Halep didn't play badly, it was just a high quality match, so much variety from Hsieh.