Boris Becker
Three-time Wimbledon champion on BBC TV

Very cool and collected start by the Serbian.

Groans from the crowd as Federer picks up a deep return from Lajovic and plonks it into the net.

The Serb takes a tumble and Federer wastes no time in rattling a winner past him, before he serves his way to a 40-15 hold.

Wonderful tennis from Harriet Dart, she's threading Karolina Pliskova all over the court like a puppet, and the British wildcard holds serve with a neat passing winner.

Right then, here she comes to a round of applause from the Court 12 faithful, who are just starting to believe Harriet Dart might get back in this match.

Play resumes at 15-30, and Pliskova quickly brings up two break points. But Dart rattles down a storming ace to scramble back to deuce.

Who do you reckon they're supporting?

Image source, Getty Images

The first point of the match goes Dusan Lajovic's way, as Federer shimmies forward and whips a forehand long.

Lajovic races to a 40-0 lead before Federer angles a return into the corner of the court for his first point. Cue round of applause.

The Serb holds with a backhand volley that Federer can't get close to.

We're still waiting for Harriet Dart to return from a medical timeout after that awkward slip.

She's broken Karolina Pliskova three times in this second set, with the Czech claiming one of those back.

The seventh seed sits in wait on Court 12.

Rightio then, here we go.

It'll be Dusan Lajovic to serve and get us under way.

So, who is the man bidding to stop Federer in his tennis tracks?

Serbia's Dusan Lajovic has reached the second round at Wimbledon twice, but he's never progressed any further than that.

He's only claimed four Tour-level victories on grass since 2014 and his best result this year is reaching the semi-finals on the Lyon clay.

However, he pushed world number three Alexander Zverev to five sets at Roland Garros and he toppled Juan Martin del Potro, then ranked sixth, in Madrid.

Image source, Getty Images

US Open champion Sloane Stephens is also about to get under way - watch that one over here.

This is the 20th (TWENTIETH!) consecutive year that Roger Federer has played at Wimbledon.

He's bidding to become the ninth player in history to win nine titles at SW19, following in the footsteps of Martina Navratilova.

His Wimbledon warm-up involved beating Milos Raonic to claim the title in Stuttgart and reaching the final at Halle, where he was shocked by Borna Coric.

Fed hasn't lost in the first round at a major for 15 years, when he was beaten in the opening round of the French Open by Luis Horna.

Image source, EPA

The players are going through their warm-ups on Centre Court.

They've flashed up their stats on screen. Just the 98 singles titles for Rog...

There's a distinct cricket theme to the guests taking their seats in the Royal Box today.

England women's captain Heather Knight and bowler Anya Shrubsole are in attendance as well as Test Match Special's Phil Tufnell and former fast bowler Bob Willis.

Singer Ellie Goulding is also here as well as actor Matthew Goode, who is currently playing Lord Snowdon in The Crown.

Former Formula 1 champion Sir Jackie Stewart and triple jump world record holder Jonathan Edwards will also be enjoying the Royal Box hospitality.

And Roger Federer's parents Robbie and Lynette can enjoy watching their son start his quest for a ninth Wimbledon title from the posh seats.

BBC Red Button

If you're in the mood for a bit of Federer, whack on the Red Button now.

Or you can pick from a whole host of streams over here.

Here the players come.

There's an almighty roar as a casual-looking Roger Federer, bedecked in his usual headband, makes his way onto court. Dusan Lajovic looks slightly more nervous.

Harriet Dart is having some treatment, with the physio tending to her left leg. Looks like she might have tweaked her knee? It's being pulled and pushed in all directions to test it out.

Sam Smith
Former British number one at Wimbledon

That was a nasty tumble for Harriet Dart and took a nasty bang on her right knee. She did the right thing by staying down until she was sure it was nothing really serious. Let's hope she okay because she is right in the heart of this match and playing brilliantly.