Roger Federer hits a backhand slice with such vicious spin that the ball scoots through too low for Rafa to get any meaningful string on it.

Fifteen-all.

That is not the sort of jam that Federer is a fan of. The Swiss is an uncharacteristically clumsy jumble of limbs as he tries and fails to fend off a fierce body serve.

Nadal splatters a superb off forehand winner on the next point and is over the finish line in this game.

Image source, AFP

Boris Becker
Three-time Wimbledon champion on BBC TV

It's wonderful to see these great legends, the GOATs*, keep finding a way to push each other and improve every year.

The next generation just don't seem to close the gap.

(*Greatest of all-time, but you knew that, right?)

Hush my mouth.

Roger Federer pings down a couple of aces on his way to a love service hold.

Both players have added beef to their serves over the years and Federer's especially is more encrypted than a Security Services email.

Image source, Getty Images

Rafael Nadal pings down a ligament-wrecker of a serve, right to the back of the box to move to 30-0.

A spotless ace thuds into the backboards to move him to 40-0.

Clinically clean ball striking from the Spaniard so far.

Federer nets as Nadal gets right up onto his toes at the baseline.

Two rock-solid service games so far. Nadal's perhaps the marginally more impressive.

Image source, Reuters

Jel: Rafa v Roger. The biggest one on one rivalry in any sport in my lifetime. Living legends.

Rachel T: I love Roger, but I have a feeling it will be Rafa in straight sets

Daniel Woodley: Legends of this game. May the best man win! Good luck to both.

Image source, EPA

Boris Becker
Three-time Wimbledon champion on BBC TV

They still love this because of the other.

One would be sad when the other player stops. It's a love-hate relationship - they're going to beat each other up today.

Jonathan Jurejko
BBC Sport at Wimbledon

Pretty sure there is not one single person in the 15,000 crowd who hasn’t already focused their camera phone on to the court.

More technology and social media here than the Silicon Valley.

Roger Federer fires an ace down the T with the first stroke of the final. Like a silenced sniper rifle, ruthlessly accurate.

Rafa Nadal nibbles back a point, but is not yet reading the Federer tee-off.

He slips 40-15 south.

Federer misses his mark with a backhand down the line as Rafa was rooted to the baseline. But Federer whacks away a mid-court bounce to seal the deal.

Image source, Getty Images

Right, both players return for a sip of isotonic and final towel down.

Stomach in, chest out, deep breath, here we go.

Roger Federer to serve...

Jonathan Jurejko
BBC Sport at Wimbledon

Excitement. Tension. Anticipation.

#Fedal40 is ON!

An electric atmosphere on Centre as the two heavyweights saunter out. The only thing missing is boxing-style ringwalk music.

I've got Eye of the Tiger in my head.

Image source, BBC Sport

Lyndsay Lomax: Trying to decide who you want to win out of Roger and Rafa is like trying to decide which one of your two children you would save from a burning building.

Vicks: Fedal time! VAMOS RAFA!!!! Time for the king of clay to become king of grass again!

Charlie Booth: What an absolute joy it is seeing Federer and Nadal against other. Two absolute KINGS of the game.

Image source, Getty Images

"Rafa has improved so much over the years on this surface. He's also playing very differently.

"I remember back in the day how he used to serve, and now how much bigger he's serving, how much faster he finishes points."

Image source, Reuters

"Playing against Roger is always a unique situation. I'm excited to be back on Centre Court against him after 11 years. It means a lot for me and probably for him, too.

"The opportunities to play against each other are becoming less, but we still here.

"I'm not expecting to learn new things about him. I just expect to play against probably the best player in history on this surface.

"I know that I have to play my best."

Image source, Getty Images

This was the first of Roger Federer and Rafael Nadal's 40 matches at Tour level.

Miami. 2004. Nadal was a 17-year-old upstart, Federer was the 22-year-old world number one and top seed. The Spaniard prevailed 6-3 6-3.

"I've heard a lot about him and saw some of his matches, so this is not a big surprise," said Federer.

"He hit some really incredible shots, and that's what youngsters do."

And the old boys as well.

Image source, Getty

Alan Coombe: I was in Majorca when the 2007 match was played...the island just stopped...there were no buses...no one could drag themselves from a screen to sell you a drink...you just took one...heaven knows what it was like in Berne or Geneva..the world economy likely took a backseat.

James Cracknell: Man, I remember watching Federer v Nadal in 2008 like it was yesterday. I can even remember going for a jog during the rain delay. Everyone who watched it went through an emotional rollercoaster. Tennis, and sport, at its best.

Abinash Das: Both the players will need to play out of their skins to qualify for the coveted finale. It was an unstoppable force (Nadal) vs an Immovable object (Federer) in 2008 classic. Will it be the same or roles are reversed? A treat for tennis purists.

Jonathan Jurejko
BBC Sport at Wimbledon

A hop across a pretty water feature from Henman Hill is the ticket resale queue. That's where people are hoping they can bag a spare from someone who has to leave Centre Court early.

Baffles me why they would have to leave, but anyway...

That is where this Fed Head immediately catches the eye.

Image source, BBC Sport

Roberta Bianchi is from Lugano in Switzerland and arrived in London last Friday to camp in 'The Queue.'

She was in a tent in Wimbledon Park for two nights to make sure she was near the front of the resale line today.

"Roger is a genius. He is never boring. I've seen many players over the years but I have never seen anybody play like him," Roberta says.

"I'm confident I'll get in today - I'm 17th in the queue."

And those who are successful will only have to scrabble around in their pockets for a few battered coins and notes. The price of a resale ticket? £15.

The ball kids stand to attention on the sides of the court.

The crowd start to hum with anticipation, the atmosphere is twitchy with excitement.

And then we see the two protagonists...

Roger Federer, aura of an emperor presiding over his court, is ready at the door. Rafa Nadal, toe touching and quad flexing, lurks behind.

And here they come....

Louis Kelly: they don't come any bigger than this.

Sumayia Asif: Palpitations. One more grass meeting between tennis’s favourite duo. I love Rafa but Roger has all my support today. Go Rog!