Image source, Getty Images

Canada's Felix Auger-Aliassime after reaching the quarter-finals: "I've played a few rollercoaster matches in the course of my career but this is at the top of the charts. It was a crazy match!

"Great level, high intensity, high focus. He's been on a winning streak on grass and the level kept being high. I'm thrilled to get through.

"More than four hours and that's a lot of work, a lot of milage in the legs but I'm excited for what comes next."

On facing Novak Djokovic in the last eight: "I heard it's a Serbian player, not so bad. I don't know much of him but I'll try to watch some videos and get ready!"

Andrew Castle
BBC Sport tennis commentator on BBC One

There is just a little bit of frustration beginning to build for the world number one.

He certainly isn't having it all his own way out there. He is getting pulled around the court a bit more now.

Jannik Sinner gives nothing away on serve as Shintaro Mochizuki is unable to get any of his returns in play.

The world number one made that look easy.

A little bit of frustration from Jannik Sinner as Shintaro Mochizuki sticks around in a point and it pays dividends as the Italian world number one hits a backhand long.

Mochizuki goes on to secure another hold to love when Sinner rasps a shot into the net.

Todd Woodbridge
Former Wimbledon doubles champion on BBC One

This match-up might actually be a good one to help Jannik Sinner find some form.

In points like that, he has time on the groundstrokes and he is finding beautiful timing. Now he is getting the pinpoint accuracy to go along with it.

That's a bit of a shame. Alejandro Davidovich Fokina tries to shake hands with Felix Auger-Aliassime before he walks off court.

The Spaniard seems to be trying to explain the situation, I think it is to do with this injury at the end of the fourth set, but Auger-Aliassime is still not having it.

No hand shake then and Davidovich Fokina shrugs and walks off to a good ovation from the Court One crowd.

It feels like Jannik Sinner has another gear or two he could move up to if he wanted.

The defending champion shows signs of it there with a lovely forehand winner after adjusting to an awkward bounce off the net, before seeing out the game with an ace.

Colin Fleming
Former British tennis player on BBC One

Shintaro Mochizuki has the game plan to maybe nick a set here. It is just that it is such a low-margin game plan against such a great player. It is hard for him to execute it consistently, but I don't think he can change anything.

He cannot afford to stay on the baseline longer or stop going into the net. He has to look for the shorter balls or look off both wings to take the ball early down the line.

He has the game plan, it depends how consistent he can be with it.

Shintaro Mochizuki is serving well now and Jannik Sinner is unable to get any returns in play in a hold to love.

Jannik Sinner eases to 40-0 as Shintaro Mochizuki lets a couple of unforced errors slip, before wrapping the game up with another big first serve.

Groans from the crowd as Jannik Sinner misses a forehand at the net before Shintaro Mochizuki serve and volleys to perfection.

Mochizuki then secures a hold to love as Sinner smashes a forehand wide.

Decent start to the second set for the world number 151.

Elsewhere, Hubert Hurkacz has just returned to court two after leaving to receive some treatment for an injury when down advantage at 5-5 in the fourth set.

Hurkacz said he wouldn't be able to continue if he didn't get that treatment. He lost the final point of that game against Jan-Lennard Struff and has just stepped up to serve.

The Pole isn't moving great and does appear to be in discomfort and has been broken to hand over the fourth set.

Hurkacz is asking the umpire if he can leave the court to go and get changed but he's been told he can't. He's not too happy and they are going into the fifth set.

Image source, Reuters

Andrew Castle
BBC Sport tennis commentator on BBC One

Shintaro Mochizuk had his chances, but Jannik Sinner holds in the opening game of this second set.

He is playing a man who was on a 30-match winning streak coming into the French Open, which creates something of a legend. I don't know how you define a great, but Sinner certainly is.

Harry Poole
BBC Sport at Wimbledon

While he is the huge underdog here, only 150 men's players worldwide can lay claim to being better ranked than Shintaro Mochizuki.

Yet, up close, the ferocity with which Jannik Sinner is hitting the ball - the speed, the power, the precision - is just on a completely different level to his opponent.

The Centre Court crowd are rallying behind Mochizuki, who continues to dig in as best as he can, but unless the qualifier can change something up it feels like there's only going to be one outcome.

Shintaro Mochizuki goes toe to toe with Jannik Sinner in a rally but skews a forehand wide when well positioned.

Sinner then wraps the game up with an ace.

Shintaro Mochizuki brings up break point with a powerful backhand down the line but can't make it count as Jannik Sinner nails another big first serve.

Jannik Sinner is facing a bit of resistance here as Shintaro Mochizuki works his way to deuce.

Sinner gets out of trouble with a sixth ace of the match, but plants a backhand into the net next point.

Deuce again and some murmurs of encouragement from the crowd for Mochizuki.

Todd Woodbridge
Former Wimbledon doubles champion on BBC One

A beautifully constructed point by Shintaro Mochizuki.

He has to start taking some risks. If there is a ball that lands a little short, he has got to take it early and come forward. I know Jannik Sinner has some terrific passing shots, but that's the only thing he can do to try to take time away from his opponent and move forward.

Otherwise, he is going to be pushed off the baseline far too quickly.

Felix Auger-Aliassime runs around a second serve and hammers a forehand winner - double break secured.

The third seed is closing in on the quarter-finals again and another comfortable hold, in which he sends down ace number 24, means he can almost taste it.

Alejandro Davidovich Fokina has battled hard but the 22nd seed is surely done now?