Already Raducanu has three break points.

Mertens keeps her composure to save all three, the third with a really nice passing forehand down the line. Deuce.

Well, that sets out Raducanu's stall for this second set.

A lovely little forehand at the net to the opposite side of the court. Using her speed to get to the net and then taking advantage of the full width of the court. 0-15.

Not too dissimilar to that superb shot she played the other day against Renata Zarazua in the first round.

Tracy Austin
Two-time Grand Slam champion on BBC TV

I like the consistency from Emma, from the beginning to the end.

The intensity stayed the same throughout. She’s broken down the forehand of Mertens.

Jonathan Jurejko
BBC Sport at Wimbledon

If Monday was winning ugly, Wednesday is winning pretty.

Raducanu is fully locked in. The Brit gives a little shake of her racquet as she bounds back to her chair.

The hubbub at the end of the set signals the punters are very happy at what they've seen over the past 40 minutes.

There was a bit of controversy earlier in this set, with the umpire potentially missing a double bounce. Have a watch and make up your own mind.

Alan Jewell
BBC Sport at Wimbledon

A really loose game from Naomi Osaka hands over a break of serve to Emma Navarro, who didn't have to do a lot to earn it. Four points, four errors and the 19th seed strikes first.

Three break points for Emma Navarro, on the Naomi Osaka serve. That's the first chance for either player to gain a break - and the American takes the first of those three opportunities to move 4-3 ahead in the opening set.

That'll do it!

A dominant opening set for Raducanu. Consistent, brilliant ball striking and confident.

What more could you ask for?

What a way to save break point!

Mertens plays the drop shot and Raducanu puts the burners on to reach it then send a glorious return down the line.

A big serve gives her set point.

Annabel Croft
Former British number one on BBC Radio 5 Live and BBC Sounds

The direction of serve from Emma Raducanu has really improved. She is desperate to close out this first set and keep that level going.

It has been a swift first set.

A hold to love from Naomi Osaka is instantly followed by the same from American Emma Navarro, the 19th seed.

Woops. Raducanu goes long and that hands Mertens a break point and an opportunity to stay in the set.

Still on serve in the second match of the day on Centre Court after a hold to love from Japan's Naomi Osaka.

The match before, Daniil Medvedev's four-set win over Alexandre Muller took almost three and a half hours, and there's still another match to come with the tasty all-Italian clash between current world number one Jannik Sinner and former Wimbledon runner-up Matteo Berrettini.

Annabel Croft
Former British number one on BBC Radio 5 Live and BBC Sounds

The rhythm of the match is really suiting Emma Raducanu.

Elise Mertens is wanting to go up against Raducanu with her own game style and she is definitely coming off second best with that at the moment. I wonder when she is going to start changing things up.

She is running out of time in this set to do that.

Raducanu has been so positive and on the front foot, really taking charge in these rallies.

A first game on the board for world number 33 Mertens.

Raducanu will have to serve it out.

Can Raducanu take this game too and prevent Mertens getting a single game on the board in this opening set?

Her passing forehand down the line clips the net and she holds her racquet up in apology as Mertens can't get to it. I doubt she's that sorry.

Ashleigh Barty
Three-time Grand Slam champion on BBC TV

I think you can see the confidence oozing from Emma at the moment. She’s come off two tournaments winning more than a couple of matches in a row.

She has more tennis under her belt than she has in years.

Image source, Getty Images

A big roar from Raducanu as Mertens fires into the net then follows up with a brilliant serve to take the hold.

An important game. She won't want to give Mertens any glimmer of momentum.

Already Raducanu is one game away from the opening set.

Annabel Croft
Former British number one on BBC Radio 5 Live and BBC Sounds

Emma Raducanu looks unplayable at the moment, such beautiful ball striking. She has always had a very compact, neat and tidy game.

She doesn't look like things can go too wrong.

She is just soaking up whatever is being thrown at her at the moment.

It looks like everything she is touching is turning to gold.

Jonathan Jurejko
BBC Sport at Wimbledon

The nerves of the opening day have been left in the locker room.

Emma Raducanu's ball-striking has been much cleaner and confident in these opening 25 minutes.