Martina Navratilova believes Johanna Konta has got the game to win a grand slam title.
The British number one will contest her fourth – and most unexpected – slam quarter-final at the French Open on Tuesday when she takes on seventh seed Sloane Stephens.
Konta will be the underdog but everything she has achieved on clay so far this season has significantly exceeded expectations and she beat Stephens on the surface in Rome last month.
Navratilova said: "You have got to get to the finals first. But yes, she has got the game. On a given day, she can bother anybody. It is a matter of stringing it together for seven matches – that is the trick in a major."
Navratilova has been as surprised by Konta's emergence as a clay-court force as anyone, saying: "It came out of nowhere really. Maybe she expected it but we really didn't see it because she had not won a match here.
"Then she gets to the final of Rome, which gives her a lot of confidence. She ran out of gas in the final because she played too many three-set matches I think. That gives you a lot of confidence and clearly she has backed it up here.
"Clearly she can play on any surface – she has got a nice game for anything. Maybe she didn't surprise herself but she has certainly surprised us."
Defending champion Simona Halep is looking very strong in the top half of the draw but Stephens appears the major hurdle to overcome in the bottom half, with Czech teenager Marketa Vondrousova taking on Croatian Petra Martic in the other quarter-final.
Stephens won her maiden grand slam title at the US Open in 2017 and reached the final here 12 months ago, winning the first set against Halep.
"Jo has to play a solid match because Sloane defends so well," said Navratilova. "Heavier conditions might be better for Sloane because she can defend that much better.
"At the same time, that will allow Jo to swing more and not miss because the balls are a little bit heavier. But, overall, Jo has to play a really solid match and pick the right shots to go for it.
"If she goes for too much, too soon, that will be trouble, and if she waits too long, then also Sloane can go on the offensive, too. The way she is playing and as confident as she seems, it is definitely possible."
There could be rain at Roland Garros on Tuesday, and former world number one Lindsay Davenport agreed that slower conditions would favour Stephens, who defeated former French Open champion Garbine Muguruza in the third round.
"Sloane is a tough out on these courts," said the American. "You saw that against Muguruza. She starts moving better, she starts getting all these balls back, she refuses to miss.
"You don't see this side of Sloane necessarily in the other tournaments week to week on the tour but I saw it here last year, I've seen it again here this year.
"Sloane impressed me so much against Muguruza. I thought Muguruza was the favourite based on how they played the round before but Sloane found something special in that match.
"Sloane's going to get a lot of balls back into play. With the conditions, I think that helps Sloane. Slow it down a little bit for her, but who knows? If Konta gets hot and is hitting her spots, I feel like she could beat anyone."
