Day 11: Three things to look out for

 - Dan Imhoff

Four singles semi-final berths are on the line on Wednesday with defending champions and the world No.1 in action

Novak Djokovic and Matteo Berrettini will square off at Roland-Garros in the night session on Wednesday, where the crowd will be allowed to stick around beyond 9pm for the first time this fortnight.

>> FOLLOW DJOKOVIC V BERRETTINI LIVE SCORES HERE

The winner will take on 13-time champion Rafael Nadal or Diego Schwartzman in the men's semi-finals.

Coco Gauff or Barbora Krejcikova will reach a maiden women's singles Slam semi-final, while fellow first-time quarter-finalist Maria Sakkari could do the same should she upset defending champion Iga Swiatek.

Berrettini up to Djokovic task

Berrettini will have looked on eagle-eyed as his young compatriot Lorenzo Musetti had world No.1 Djokovic rattled for two sets on Monday.

The 18-year-old Musetti eventually capitulated as Djokovic closed rapidly on the finish line, however, it was enough to have boosted Berrettini’s belief that his prospective opponent is beatable.

>> ORDER OF PLAY: WEDNESDAY DAY 11

The 25-year-old Berrettini was handed a walkover after Roger Federer withdrew, but brought form, having claimed his first title of the season at the Serbia Open before his first Masters 1000 final in Madrid.

The Italian ninth seed has righted his course since a disappointing defeat to Daniel Altmaier in the third round at Roland-Garros just eight months ago.

“When I struggle, I struggle. When I'm happy, I'm happy. But before it was a little bit too dark,” Berrettini said. “I have to work, and I'm proud of what I have done. Now I'm really looking forward to play next tournaments, next matches, because at the end now I feel I'm back again.”

Djokovic, too, came into Roland-Garros on the back of a title in Belgrade and a Masters 1000 final – in Rome – leading in. He is well aware of the threat the top Italian poses.

“A big serve, big forehand. Two big weapons. He's in form,” said Djokovic, who holds a 1-0 head-to-head record. “He's very aggressive. You know, with his big serve he's got a lot of easier balls in the middle of the court that he can penetrate through the forehand or he can drop shot. He's very good at the net. He just has so much firepower in his game.”

The reward for the victor is a showdown with either 13-time champion Nadal or Argentine 10th seed Schwartzman.

In a rematch of last year’s semi-final, Schwartzman knows it will be an uphill battle to overturn a 10-1 head-to-head in the Spaniard’s favour.

“I think at the beginning of every match against Rafa, you have to walk on the court thinking to win the match, to have opportunities, to get opportunities, and think about something else and not think about Rafa in the other side of the net,” Schwartzman said.

Swiatek ready to cast friendship aside

The scoreline proved deceptive but the result was a profound warning to future challengers on Monday night as defending women’s champion Swiatek overcame a hyper-aggressive Marta Kostyuk in straight sets.

The eighth seed reached her second straight Roland-Garros quarter-final to set a last-eight showdown with 25-year-old Greek, Maria Sakkari. It will be the pair’s first meeting and the Pole admits friendship will take a back seat once they enter battle.

“It's never easy to play with one of the nicest girls on tour. But, yeah, I mean, tactically I'm going to for sure be prepared,” Swiatek said.

“She's the kind of player who likes to play defence as well, as [Kostyuk]. I'm just going to be ready. I'm going to be patient and hopefully it's gonna get results.”

Sakkari is eyeing her third straight seeded upset having seen off Belgian 14th seed Elise Mertens and last year’s runner-up Sofia Kenin in succession.

First major semi-final up for grabs

Gauff admits she is still learning the art of playing on clay and even concedes it only comes in at No.3 on her list of preferred surfaces.

That could all be about to change should she find a way past fellow first-time Slam quarter-finalist Krejcikova on Wednesday. The 17-year-old comes off a win over fellow former junior champion Ons Jabeur to become the youngest American in the last eight since Jennifer Capriati in 1993.

“My message has always been ‘dream big and aim higher’,” Gauff said. “I could have easily said I'm satisfied with fourth round and everything, but today I think I just came in more hungry and wanting more compared to my last times I have been in the fourth round.”

For the unseeded Krejcikova, the second-week has been a longer time coming, in singles at least. The 25-year-old has already shared in the Grand Slam spoils as a women’s doubles champion at Roland-Garros and Wimbledon in 2018 and in mixed doubles at the Australian Open for the past three years.

This Roland-Garros, though, marks only the second time she has passed the second round at a major in singles with wins over the likes of former finalist Sloane Stephens and fifth seed Elina Svitolina to boot.

Having faced Gauff in doubles, this, she knows, is a huge opportunity for both in singles.

“She's young, she's amazing, she's coming up,” Krejcikova said. “You know, she's gonna be the next star.”