In round two, Joao Fonseca came from two sets down to beat Dino Prizmic in five.

In round three, he came from two sets down to beat Novak Djokovic in five.

Will he be able to do it again?

An hour and 23 minutes played on Court Philippe-Chatrier and Jakub Mensik is into a two-set lead.

Mensik just seems to be a step ahead of Joao Fonseca at the moment.

A double fault by Joao Fonseca brings up a second set point in this game for Jakub Mensik.

Saved with a great forehand winner by Joao Fonseca that kisses the sideline.

A shake of the head from Joao Fonseca as, on another game point, he goes just wide with an overhead smash.

Jakub Mensik puts away a mid-court forehand - set point for a two-set lead...

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Goodness me, Jakub Mensik's volleying is from another world tonight.

He gets to one right by his feet and drops it stone dead over the net. Perfection.

That makes it 30-30 and Joao Fonseca nets on game point for deuce.

The crowd on Court Philippe Chatrier try to get behind Joao Fonseca a little bit at 30-30, but Jakub Mensik closes out the game from there.

He hasn't faced a break point yet in this quarter-final.

A hold to love for Joao Fonseca, with Jakub Mensik guilty of some unforced errors in that latest game.

He still has the advantage in the second set, though.

This is superb stuff from Jakub Mensik. Very impressive.

A brief aberration as he finds the net with a backhand volley, but he puts away an overhead smash on the next point to move 4-2 ahead.

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Jakub Mensik reached his career-high ranking of 12th earlier this year.

Being knocked out in the last 32 of the Masters 1000 tournament in Miami, an event he won last year, meant he lost a lot of ranking points.

He started the French Open in 27th spot but he'll jump into the top 20 if he wins this quarter-final, as will Brazilian teenager Joao Fonseca, who has never previously been higher than 24th in the world.

Superb again from Jakub Mensik to secure the break!

He advances to the net and puts away a forehand volley winner to move in front by a set and a break.

You will struggle to find two better points from deuce than that.

Joao Fonseca was 40-0 up in that game - how costly will that prove to be?

Ohhh, magnificent defence from Jakub Mensik, followed by a dream of a backhand passing shot, and the Czech has a break point.

From 40-0 up, Joao Fonseca's level drops a bit and suddenly it's deuce.

A chance for Joao Fonseca as Jakub Mensik squeaks a forehand just wide - 0-30.

But the 6ft 5in Czech finds some more first serves at just the right time, ending the game with a couple of aces.

Both players are serving tremendously well in the first set and a bit.

Joao Fonseca is at 76% of first serves in, Jakub Mensik at 70%.

Most players would be probably happy with anything over 60% over the course of a match.

Fonseca holds again for a 2-1 lead in the second set.

Joao Fonseca absolutely crashes a forehand away for a winner and 15-15. When he hits them, they stay hit.

But Jakub Mensik is proving a tough nut to crack - he's looking extremely solid and is picking up cheap points because of his serve, which is a tremendous weapon.

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Joao Fonseca is aiming to become the first teenager to reach the last four of the men's singles at a Grand Slam since Carlos Alcaraz at the 2022 US Open.

The most recent teenager to do so at the French Open was Rafael Nadal in 2005.

A hold to love for Brazilian teenager Joao Fonseca at the start of set two.

The 20-year-old has the advantage against the 19-year-old.

One break of serve midway through the first set is enough for Jakub Mensik to take it.

He brings up two set points thanks to an excellent half-volley at the net, and although the first one goes begging, Mensik puts away a forehand volley to secure a one-set lead.