Nadal has switched to "business as usual" mode.

After breaking Yuichi Sugita in the opening game of the second set he holds to love in the second.

"Mariaaaa, you should have seen her... get taken to a deciding set against French world number 88 Pauline Parmentier"

The 2004 champion (and current world number 80) looked set to book a round-two encounter against world number 31 Carla Suarez Navarro, but has now been taken to a third set after losing the tie-break.

Image source, Getty Images

Well, well, well.

Serena Williams tugs her forehand into the middle of the net to hand Guilia Gatto-Monticone two break points at 15-40.

And a look at a second serve.

Serena marauds to the net on the next point. And Gatto-Monticone threads the ball down the line to break!

Andrew Cotter
BBC Sport commentator at Wimbledon

Yuichi Sugita looks to be fading fast.

Even though we're still at a fairly early stage Rafael Nadal is now bossing things entirely.

Image source, Getty Images

Post your guesses using #bbctennis - try not to use a search engine.

Answers later.

Katie Falkingham
BBC Sport at Wimbledon

Sounds like there is a Gatto-Monticone fan sat a few metres away from me. “Come on Giulia, give her a push girl,” he cries.

He repeats this several times. Each time getting more high-pitched. I think someone’s had too much Pimm’s...

Unfortunately for him, it’s not helping much. The Italian, who has heavy strapping on her left knee, doesn’t look to even be attempting to meet some of Williams’ returns.

Williams is in cruise control without having to break much of a sweat.

Serena Williams has a set point after just 21 minutes.

But Guilia Gatto-Monticone knocks her back at 30-40 and then slaps down an ace to get on the board.

Big cheers from the crowd. A bagel is off the menu...

Tim Henman
Former British number one on BBC TV at Wimbledon

When you reflect on Rafael Nadal's previous early round defeats, they're all against players who have one big weapon in their arsenal.

Yuichi Sugita doesn't really have one weapon - he's a bit of an all-rounder. It will be a massive challenge for Sugita if he's to upset Nadal.

Nadal wraps up the first set after an early hiccup when he was broken in his first service game.

He also fell over after delivering his first serve.

It happens. Only true champions know how to pick themselves up after slipping over in front of thousands.

True champions.

Johanna Konta on BBC Two after beating Ana Bogdan to reach round two:"It was very tough out there. Neither of us felt quite comfortable at first and it wasn't easy but you always have these kind of battles in the first rounds of Grand Slams. I just tried to find my level and I did that.

"I think I played a lot of matches in the run-up to Paris and I'm building on each match I'm playing now. I'm reading the game better and expressing myself better on court.

"I didn't play my best tennis today against a good opponent but I competed well which is important."

Serena Williams is finding the sickly-sweet centre of the strings. Each shot is coming off the racquet with a percussive 'pock!'

Giulia Gatto-Monticone, ranked 161st in the world and a loser in her one other meeting with a top-20 player, is right up against it.

Image source, Getty Images

Won't someone think of the children? This sort of carnage is only usually shown post-watershed. Serena Williams breaks to love amid a cacophony of clattering forehands.

Giulia Gatto-Monticone is chasing the lengthening shadows.

Ian Evans: The atmosphere on centre court is electric.

Serena is definitely playing short of her best. Something is bothering. She returned to her chair for a towel down after the first game, when she usually takes a route around the other net post. She is moving in a slow, considered way between points and is not raising the tempo much higher when play is underway.

Giulia Gatto-Monticone gets a look at 15-40, but the two break points are whipped off the table before can cash them in.

Look at the video still - that must be the four millionth time he's celebrated in that way at Wimbledon.

It was fairly routine in the end for "Sir Roger" despite losing the first set 6-3 to South African Lloyd Harris.

Any hopes of a shock the debutant had were soon extinguished as the eight-time champion knocked off the next three 6-1 6-2 6-2 in front of a delighted Centre Court crowd.

Number nine is still in sight.

I hope Giulia Gatto-Monticone has kept her receipt because her serve has just been taken to the cleaners.

Serena Williams is mashing returns and punches a 0-40 shaped hole in the hull of the Italian.

She converts on the second. Even if she is not at full-bore i think she is going to have too much for the over-matched Gatto-Monticone...

Back on Court One, both Rafael Nadal and Yuichi Sugita are producing some great tennis.

Having broken each other, it's now back on serve.

Worrying for the Japanese world number 274 his more decorated opponent has rediscovered his mojo.

Image source, Getty Images

Katie Falkingham
BBC Sport at Wimbledon

Serena Williams’ serve isn’t there in the early moments of this encounter. I’ve lost count of the number of times she’s clipped the net and we’ve only played one game!

Every time the umpire calls “let” there’s a nervous giggle among the crowd. Do they laugh, or should they be worried? They don’t know!

The first point goes to Giulia Gatto-Monticone as Serena Williams put a bit too much sauce on her groundstroke.

And the American great does not actually look like she is moving too smoothly.

She is teeing off from the baseline and does not look comfortable as she comes forward and volleys long to allow Gatto-Monticone to deuce.

Serena's power blows the doors off to take the game.

Image source, Getty Images