Blimey!

Two break points as Nishikori produces a great winner.

He then stays put in the middle of the net to put away a volleyed winner.

Wow! And double wow!

That's effective, pumping a volley so hard into the turf it skips up and into the crowd behind... Nicole Melichar leaves Andy Murray swiping at thin air. Bruno Soares holds to love.

Chanda Rubin
American former world number six at Wimbledon

Soares did a fabulous job on return from the start of that game. It helps to erase the disappointment of how the second set ended.

And the top seeds take the early advantage in the final set.

Nishikori is passed as he tries to outfox Fed with a drop at the net.

15-0.

The Japanese eighth seed levels with an angled-double hander.

15-15.

Touche mon ami.

Oh no. Serena Williams puts everything into a rising smash, but looks down to see the ball by her feet after only finding the net tape.

Break point Soares and Melichar.

"Let's go, come on..." Andy Murray senses the opportunity now.

He rips down another first serve and meets Bruno Soares' return on the volley, but Nicole Melichar is there to paddle it into the space left behind.

30-30.

Chanda Rubin
American former world number six at Wimbledon

As the game went on Soares started going through the serve faster and faster. Nerves, tension, the moment - all of that got to him.

That second set was a bit better for Murray and Williams. They got more aggressive and put additional pressure one.

In Oxford: Watching the #Wimbledon, external mixed doubles #BBCtennis, external match with #MuRena, external and wondering if anywhere has considered hosting a top-level "doubles & mixed only" #tennis, external tournament so there's nothing stopping the top singles players from teaming up & going up against doubles specialists.

Annie Day: I can’t say I’ve ever spent an afternoon glued to the doubles but seeing @andy_murray, external laughing on court with @serenawilliams, external is just joyous.

Sami Sumner: The Umpire presiding over the Serena Williams and Andy Murray doubles match against Soares and Melichar might possibly have the best voice in #Tennis, external but also what a game!!

Another double from Bruno Soares - his third in that service game alone, remarkable.

The fans on court two aren't complaining. Andy Murray and Serena Williams hit back to take the second set.

This one is going to a decider...

Image source, Getty Images

Melichar bails her partner out with a volleyed smash to save the first.

Two set points to go.

The court two crowd love that, a rasping Williams return that skids beyond Soares and gets hand pattering in appreciation. Soares dishes up a double fault, and another...

Three set points.

An easy hold for Roberto Bautista Agut to start the fourth set.

Chanda Rubin
American former world number six at Wimbledon

It's been a clean match from Soares and Melichar. They're forcing Murray and Williams to play doubles the right way. It's been a very enjoyable match to watch.

Image source, BBC Sport

Here comes Roger...and Kei.

The Centre Crowd greet both warmly.

The pair have played each other 10 times but only once on grass.

That was at Halle five years ago, where unsurprisingly Federer came out on top.

Zing! A scream to pierce the ears as Serena Williams unleashes a mammoth backhand volley. She and Andy Murray hold. They're one game away from taking the second set...

Oh dear... is that ballboy a Murrena fan?! He goes chasing a loose one, bumps into Bruno Soares and almost knocks the Brazilian off his feet. Luckily, Soares sees the funny side.

Textbook serve-volley combo from Andy Murray to stride in and win the point at 30-15.

Katie Falkingham
BBC Sport at Wimbledon

If Roger Federer beats Kei Nishikori, it will be his 100th match win at Wimbledon, meaning he would become the first player in history to win 100 men's singles matches at a single Grand Slam event.

Remarkable.