Lindsay Davenport
Former Wimbledon champion on BBC TV

It's always tough to play back-to-back days, especially at majors when there's even more tension and pressure. 

Serena Williams holds in the opening game and then earns break point on Svetlana Kuznetsova's serve.

They move to deuce when Williams hits long, and Kuznetsova has the advantage...but then she double fault. Back to deuce.

Eventually, Kuznetsova sees it out. 

Image source, AP

Peter Fleming
Seven-time Grand Slam doubles champion

Talk about stellar returning games. David Goffin played several solid returning points.

Belgian Goffin, the 11th seed, breaks Canadian sixth seed Milos Raonic

Image source, PA

The epic battle between Dominika Cibulkova and Agnieszka Radwanska featured tennis of the highest order.

Watch this rally and see for yourself. 

Sam Smith
Former British number one on BBC TV

We've already had one great on Centre Court, and here is another, four matches away from equalling Steffi Graf's Grand Slam haul of 22. 

Serena Williams is underway against Svetlana Kuznetsova on Centre Court.

It wasn't an easy ride but Simona Halep has come through in three sets against American ninth seed Madison Keys to reach the quarter-finals. 

Halep reached the semi-finals here in 2014 and will play Angelique Kerber in the next round. 

David Goffin and Milos Raonic are underway in their fourth-round match on court two.

It's going with serve so far. 

Canadian sixth seed Raonic is being watched by new coach John McEnroe, who is looking like a cool cat in his rascal head gear and shades. 

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Roger Federer speaking to BBC TV: "Best of five matches are always tough. It needs lots of concentration, the finish line is far away and it can turn really quick.

"I'm happy with how I played it is not easy as maybe it looked. Steve has picked up a lot of confidence in the last weeks and he has a nice game for grass but I think I mixed it up well here today.

"I would never have thought I would win the first four rounds in staright sets. The matches may be tough but rests are great for professional atheetes, that’s huge.

"It is nice that I have never missed Wimbledon. You can always lose a tournament in the first week but never win it.

"I now need to play my best tennis. I have Cilic in the next round, he brushed me off the court in the US Open a few years ago and I hope to get him back."

Image source, Reuters

Tom Hendryk: Worthy for any stage and any final. Not fair that someone had to lose that match. @ARadwanska, external and @Cibulkova, external that was amazing.

Lulu Gabrielle: What a game!!! Amazeballs #Cibulkova, external

It's been a hit-and-miss year for defending champion Serena Williams.

She lost in the Australian Open final to Angelique Kerber. She then lost in the French Open final to Garbine Muguruza.

But the all-dominating Serena we know and love was out on display on Centre Court yesterday.

She needed only 51 minutes to beat Annika Beck of Germany in straight sets to seal her 300th Grand Slam victory. 

Can she clock up 301 today? Standing in her way is two-time major winner Svetlana Kuznetsova - the Russian 13th seed. 

They're up next on Centre Court.

Jonathan Jurejko
BBC Sport at Wimbledon

Image source, BBC Sport

As you would expect on 4 July - American Independence Day - plenty of Stars and Stripes are dotted around SW19. 

These two fellas - Tanner Potter and Luke Salisbury - have arrived from Utah today, digging their patriotic attire out of the suitcase especially for the occasion. Bandana, vest, shorts, socks - the full kit.

The colourful pair are peering over the side of Court 18 to cheer on Sam Querrey, who they reckon can go all the way this year.

"He's beat 'Joke-ovic' so he's no joke," quips Luke.

Image source, BBC Sport

And Tanner reckons it'll be a USA double with Serena taking the ladies' title. "Why not? Sam's got a frightening serve and is looking good, and Serena's already won 21 Grand Slams. We believe in the American dream."  

Jonathan Jurejko
BBC Sport at Wimbledon

This one could disappear down the drain rather quickly for Nicolas Mahut. The French doubles specialist has never played in the last 16 of a Slam singles draw - and he doesn't look like extending that to a quarter-final after a poor start in the third set. 

Querrey rockets his way to a break in the opening game, backing that up with a hold to love. 

Mahut brings out his inner Indian Jones at the changeover, using his towel to frustratedly whip the chair into submission. 

Chris Goldsmith: HUGE win for @Cibulkova, external 6-3 5-7 9-7 v Aga Radwanska ... brilliant match, had everything, both players gave everything   

Tevon: Cibulkova vs Radwanska is the women's match of the tournament!  

Hellie Hoo: WOT A MATCH! 

Jim Courier
Former world number one on BBC TV

Federer speaks four or five languages and Johnson speaks one, American English.

Their games are a little bit like that as well.

Chris Goldsmith: That Radwanska v Cibulkova was more than worthy of a Wimbledon final   

James Stevenson: Finally! What an absolutely spectacular match from both players. Cibulkova is through to the quarter finals.  

Derek Paterson: Anyone still want to say women's tennis isn't as good? This match is incredible!

James Burridge
BBC Sport

A sensational match. A standing ovation. Matches like this, it's a shame there is a winner and loser.  

Sealed with a lovely ace.

Roger Federer sends a serve skidding down the T and out of Steve Johnson's reach to book his ticket to the quarter-finals.

He will play Croatia's Marin Cillic on Wednesday.

Image source, Getty Images