Murray unleashes a 91mph forehand winner to take Alex de Minaur to deuce for the second time in the eighth game.

Oh dear, the Aussie then double faults and Murray has the chance to break and serve for the set.

But De Minaur comes roaring back with some ruthless serving, to which Murray has no answer. What a response to that double fault. An important hold.

How Rafa reacted to Roger's retirement announcement:

Left is best: McEnroe is my hero, he was Van Gogh, crazy and talented. Then Fed came along. Picasso. A world changing artist. My other favourite.

Joanne Pen: Federer bowing out with Murray, Djokovic and Nadal all on the same team is so appropriate. He has always loved the history of the game and speaks of players like Laver with such respect and gratitude. He has elevated tennis to a new level for future generations.

With a 129mph serve thrown in there, Murray wins his third game in a row and is settling into this one nicely after a shaky start.

He gives us a big fist pump as he takes the lead for the first time.

Jonathan Jurejko
BBC Sport at the O2 Arena

Don't trip over your shoelace!

Even 35-year-old Andy Murray needs to be told that.

A laugh echoes around the stadium when Murray is given the friendly warning by umpire Aurelie Tourte.

Murray's kids, perhaps watching at home, would have enjoyed laughing at their dad too, I'd imagine.

The first real roar of the night comes after a bit of brilliance from Murray as he produces a fantastic overhead backhand to go 0-15 up before winning the next point.

A weak backhand from De Minaur gives Murray three break points.

Huge opportunity to level the match - and he takes it! The crowd are really starting to get into this one.

With Roger Federer and Rafael Nadal away to prepare for their match, Novak Djokovic has taken on the cheerleading role for Andy Murray as the three-time Grand Slam winner holds.

Now would be a good time for a break, Andy.

Andy Murray shows that, at 35, he still has plenty of speed around the court as a passing forehand forces an error from Alex de Minaur.

The Scot then produces a thundering backhand to bring his opponent to deuce.

The door is ajar...and a clinical cross-court forehand gives Murray his first break point!

Oh wow! Murray thinks he's made a tremendous backhand down the line but Hawkeye confirms it was just wide.

De Minaur then takes the next two points to extend his lead to 3-1. Gutsy.

The great one entering the arena for the last time.

Hope I look half as good at 41.

Image source, Getty Images

Andy Murray is up and running as he holds in his second service game and receives words of support from his team-mates as he heads back to his seat.

Rafael Nadal offers Murray a few pointers, too. Rafa was actively coaching his team-mates in the opening session, too. He seems to relish that part of team play.

There were some lovely tributes to Federer in this story's comments section, so we've picked out a few:

Nickmcp71: What a way to go out, playing in tandem with your greatest career adversary. Should be something very special, hopefully

Pw84: Federer turned tennis into an art form. The only true GOAT.

Untold Reality: The only player I've seen in recent years who always looked like he never broke sweat! Elegant and classical in its purest form.

We want to hear more so please do send us your Federer tributes and memories to #bbctennis!

Alex de Minaur is moving well on what is a remarkably slow court as he backs up that break with a smooth hold.

Just the start Team World were hoping for after two defeats in the earlier session.

Jonathan Jurejko
BBC Sport at the O2 Arena

Image source, BBC Sport

Outside the entrance to the O2 Arena is a practice court, where fans can line up and walk along a viewing gallery to see the players warming up.

Shortly after 5pm today they got a treat.

Fedal - doubles partners tonight and a glorious 42 major singles titles between them - hit the practice court a few hours before they go out for real in the main arena.

The queue was long as people scrambled into action after hearing what was going on.

And for those who were late to the party, they still got to see Nadal who stayed on a little longer.

Image source, BBC Sport

Roger Federer seems relaxed, laughing away with Casper Ruud courtside.

Andy Murray isn't laughing, though. He's just been broken by Alex de Minaur in the opening game.

Jonathan Jurejko
BBC Sport at the O2 Arena

Image source, BBC Sport

Camera phones at the ready... here's Roger!

A Ryder Cup-style introduction to the players of both teams before tonight's opening match.

Team World are welcomed out first. Then the volume is cranked up a notch or three.

Andy Murray receives a huge roar but that is dwarfed by the one for Rafael Nadal.

Nadal is the penultimate player. Guess who's last? Federer.

The Swiss maestro receives a near-standing ovation from the almost full O2 Arena.

Image source, Getty Images

Before Roger Federer graces an ATP Tour event for the final time, Andy Murray is in singles action.

The three-time Grand Slam champion takes on Australian Alex de Minaur.

De Minaur, 23, won their last encounter in 2019 and will surely provide a stiff test for the Scot.

That one gets under way in a few minutes.

Jonathan Jurejko
BBC Sport at the O2 Arena

Walking around the O2 Arena almost feels like milling about outside your football team's home stadium in the hour before kick-off.

Without the stench of greasy burgers.

There is almost as much red and white dotted about here as there would be before an Arsenal game. Or, I should say, a Switzerland game.

Caps, t-shirts, scarves, even earrings... all emblazoned with the initials of one player.

RF.

Image source, BBC Sport

Roger Federer has just been introduced to the crowd at the O2 Arena, along with the rest of Team Europe and their Team World counterparts.

And boy, what a reception for Fed.

This is going to be fun.

Image source, Getty Images

Image source, Getty Images

While Stefanos Tsitsipas said he'd never previously experienced anything like the protester incident on court, it failed to knock the world number six off his stride as he beat Diego Schwartzman 6-2 6-1 to put Team Europe 2-0 up against Team World.

Earlier, US Open runner-up Casper Ruud got Europe up and running by beating American Jack Sock.

The Norwegian beat Sock 6-4 5-7 10-7 despite having trailed by three points at one stage in the 10-point tie-breaker.

Ruud received plenty of support from his team-mates, especially Rafael Nadal.

"Obviously I was focused about the match and trying to win it but it is fun, you turn around and have Rafa on one side and Roger on the other trying to help.

"I didn't feel like I needed an unbelievable amount of help but they gave me some good tips."

After a disappointing start, John McEnroe's Team World will be determined to ruin Roger Federer's farewell party and fight back in the evening session.

Jonathan Jurejko
BBC Sport at the O2 Arena

Image source, Getty Images

Play was briefly stopped earlier as a protester appeared to set his arm on fire after running on court.

The young man, wearing a T-shirt with the message 'End UK private jets' on the front and back, was quickly removed by security and detained in an internal corridor.

Laver Cup organisers said he had been arrested and police were "handling" it.

The incident happened before the second set of the match between Stefanos Tsitsipas and Diego Schwartzman.

"It came out of nowhere," said Greek world number six Tsitsipas. "I never had an incident like this happen on court. I hope he is all right."

Read more here.