Now then, a rare chance for a break in this battle of the big servers.

Alexander Zverev's accuracy has deserted him for a moment, two forehands long, one into the net.

Image source, Reuters

Reaching 30-30 on Andreescu's serve represents as good a chance as any for Jabeur.

And it could get even better!

Is this a turning point? Break point.

More pressure from Andreescu on Jabeur's serve, but the Tunisian is digging in, as she must.

Jabeur slams down a timely ace for 40-30... Oh!

An Andreescu forehand is called out, Hawkeye shows the rest of us it's definitely in, but the Canadian decides not to challenge because Jabeur advises her not to!

Just as well they're good friends...

Alexander Zverev earned a break point in the first game of this match but neither player has even been taken to deuce since.

Italy's Matteo Berrettini is averaging an ace per service game so far, four in total, including two just as he held to love.

Could be decided by tie-breaks this match.

Image source, Getty Images

There's no stopping Bianca Andreescu right now.

Another hold to love starves Ons Jabeur of hope.

That's now just one point dropped in her past five service games! Solid.

Tracy Austin
Two-time Grand Slam champion on BBC TV

I wonder if Jabeur is a little rattled on serve, because Andreescu is just so aggressive on returns.

I will say I would like to see Jabeur look a little more positive. She's showing her doubts so far.

You can see on Jabeur's face how concerning these first 40 minutes or so back on Centre Court have been for last year's runner-up.

Andreescu is the one forcing the issue and playing the more positive stuff.

The Canadian senses her next opportunity as she reaches deuce, but Jabeur is able to refocus and plays a couple of neat points to edge back in front in set two with a crucial hold.

Image source, Reuters

Tim Henman
Former British number one on BBC TV

Matteo Berrettini was making such big strides in the game and he's had some unlucky moments but now you really feel like he's back building that momentum. In the last round he just took Alex De Minaur apart, who is a confident grass court player, so it really does set up nicely for this one.

Matteo Berrettini cannot believe a Zverev forehand hasn't been called out, so he challenges.

The TV replays show why he was so stunned - it's out by about a foot.

However, the Italian then butchers a forehand long himself as we stay on serve on Court One.

Ons Jabeur needs to figure out how to hurt Bianca Andreescu, fast.

The Canadian races to 40-0, before letting Jabeur on to the board with a double fault, but that's as much as she'll allow her opponent here.

Another service game in the bag.

Differing holds of serve to start proceedings on Court One.

Matteo Berrettini has to save a break point to hold his opening service game before 19th seed Alexander Zverev races through his opener to hold to love, barely breaking sweat.

If you're wondering why Zverev is so lowly seeded and why 2021 Wimbledon runner-up Berrettini is unseeded, it's because both have suffered with long injury absences in the past couple of years.

Nick Mullins
BBC Sport commentator at Wimbledon

Jabeur has not got herself into this yet. All the wires are not connecting where they need to at the moment.

Important for Ons Jabeur to make a positive start here, otherwise this could get away from her quite quickly should Bianca Andreescu maintain the level she displayed in the opening set.

Trouble.

Andreescu carries her momentum over, reaching break point after another unforced error from the currently misfiring Jabeur.

But she can't add the final touches and allows the Tunisian to escape.

Tracy Austin
Two-time Grand Slam champion on BBC TV

Andreescu has done a terrific job of dictating play and not allowed Jabeur to get into this match. She is rushing Jabeur.

That is a very impressive first set from Andreescu.

Do we have an upset brewing on Centre Court?

The Canadian has been near-perfect so far, losing just one point in her final three service games of that first set.

But Jabeur is certainly not one to go down without a fight.

Image source, EPA

We've already witnessed one thriller on Centre Court today as world number one Carlos Alcaraz had to dig deep to see off Chilean 25th seed Nicolas Jarry.

Check out the best of the action from that one below.

Tracy Austin
Two-time Grand Slam champion on BBC TV

Andreescu does not want to leave the ball in the middle of the court, where Jabeur has inside-out and inside-in options.

That was the one-two punch that Jabeur was looking for.

Ons Jabeur forces Bianca Andreescu to serve for the first set with a couple of punchy follow-ups taking her clear on serve.

The Tunisian returns to the back of the court waving her arms to try and get herself bumped up for a final shot at salvaging something from the first set.

Alexander Zverev still has a way to go to usurp the greatest player in German tennis history on a heap of fronts.

But he's got the time left in his career to do it, at the age of just 26.

Play is under way in his third-round meeting with Matteo Berrettini on Court One.

Image source, Getty Images

Jess Anderson
BBC Sport at Wimbledon

On my travels this afternoon I spotted Eurovision star Sam Ryder. (See terrible photo below)

A woman cried out ‘I love you Sam!’ and was then rather hastily ushered away as she tried to hug him while his bodyguard snatched away her Pimm’s before she could spill it down Sam’s white shirt.

With him (left of image) was Hannah Waddingham of Eurovision hosting, Ted Lasso and Game of Thrones fame.

Shame I’m too shy to ask for an autograph.

Image source, BBC Sport