Johanna Konta faces the biggest challenge of her unexpected French Open run when she takes on proven grand slam performer Sloane Stephens in the quarter-finals on Tuesday.

The British number one has done remarkably well to make the last eight at a tournament where she had never previously won a main-draw match.

Konta has been superb in her last two matches, particularly her fourth-round win over Donna Vekic, but Stephens represents the major hurdle in the bottom half of the draw.

The American is a slam winner having lifted the US Open title in 2017 and came close to claiming a second trophy here last year, when she lost the final against Simona Halep.

Konta said: "What she does well is she raises her level in tough moments. It will be a great opportunity for me to play against one of the best players in the world. It's a great position for me to be in."

This will be the pair's third meeting of the season, and encouragingly for Konta she has won both of the previous ones, in Brisbane to start the year and then, more relevantly, a few weeks ago on clay in Rome.

The 6-7 (3) 6-4 6-1 victory was the first in a string of standout results for Konta that carried her all the way to the final and proved for the first time she could be a big danger on this surface.

Not that Stephens will be reading too much into the two defeats.

"When I played her the first match of the year, totally out of my mind," said the 26-year-old. "And then the one in Rome, bad circumstances. Out of the mind.

"So I'm just going to go in with a clean slate. We play a sport, so you never know what's going to happen on the day. So just put all of that out of my mind and just go and play a quarter-finals grand slam match like I know how to."

The catalyst for Stephens' improved results after a difficult start to the season appears to have been her hiring of hugely-experienced Swedish coach Sven Groeneveld, who has previously worked with Maria Sharapova, Caroline Wozniacki and Greg Rusedski among others.

Konta also seems to be benefiting from her relatively new coaching relationship having worked with softly-spoken Frenchman Dimitri Zavialoff for seven months.

Zavialoff, who previously coached Swiss pair Stan Wawrinka and Timea Bacsinszky, has been expecting Konta to fire back into top gear having been impressed by the 28-year-old's abilities.

He said of her run here: "There's not a big difference with before. The big difference is that she is winning matches.

"It will end, maybe with the trophy, maybe not. So we just take it like this. I like how she is committed to what she is doing. I'm not surprised. It's the first impression that I had from her and I like it. It's a thing that most champions in tennis have."

The big criticism of Konta, especially during her difficult times since reaching the semi-finals at Wimbledon two years ago, was the lack of an alternative plan if her big ground strokes were not firing.

But it has been noticeable on the clay in particular how much Konta is now willing to vary her tactics, coming to the net and throwing in drop shots.

Zavialoff's central coaching philosophy is about encouraging his player to make the decisions – he refuses to come onto the court to coach during matches, which is allowed on the WTA Tour.

He said of the growth of Konta's game: "It's just showing her how good she is and to invite her to try. To try and miss sometimes and sometimes try and achieve something.

"I really don't want to control anything in there. There's one main thing for me is that the player is playing, it's not the coach. The coach is helping from time to time and a good collaboration is highly needed.

"I think she feels comfortable with that at the moment and she likes it. I think she obviously is a very good player, I would even say a fantastic player, and she shows it."

If Konta can get past Stephens, she would face either Croatia's Petra Martic or Czech teenager Marketa Vondrousova for a place in her first grand slam final.

"I can't promise that this player will win a grand slam," said Zavialoff. "What I know is that she will be tough to beat. So if anyone from the other players manages to do that, good for them."