Iga Swiatek stays perfect against Coco Gauff, reaches Roland Garros semifinals

WATCH: Iga Swiatek has yet to lose a set this fortnight in her first five matches.

Entering Wednesday's highly-anticipated Roland Garros quarterfinal between Iga Swiatek and Coco Gauff, there was one question rippling around the tennis world, from the locker room to television broadcasts: Sitting at 0-6 against Swiatek overall, including a straight-sets loss in the championship match in Paris 12 months ago, what could the American do to unsettle the world No. 1?

For much of the first hour on Court Philippe-Chatrier, Gauff did all she could. In windy conditions, she threw in different speeds, spins and shot patterns in rallies, and came to net. From her forehand, her weaker groundstroke, Gauff through in high, looping balls to Swiatek's backhand to change the pace. She broke Swiatek back right away after falling behind 3-1 early on. At one stage, she even ripped a passing shot right at Swiatek, knocking the world No. 1 to the ground. (For that, she apologized.)

But after one hour and 28 minutes, the end result was the same as it has been in every one of their head-to-head battles so far: By a 6-4, 6-2 final score, Swiatek was victorious, and improved to 7-0 in matches, and 14-0 in sets, against Gauff. She also improved to 26-2 at Roland Garros so far in her career overall.

"It wasn't easy, especially the first set was really tight," Swiatek said in her on-court interview with former Wimbledon winner Marion Bartoli. "Coco was really using the conditions, so I'm pretty happy that I was able to work on it and win this match.

"I wanted really to play without pressure and go for it."

That Swiatek did, particularly at crucial moments. She trailed 0-30 on serve at 4-4, and also 15-40 at 1-1 in the second set. In mirror imagery, Swiatek saved four of the five break points she faced, while Gauff only saved one of the five against her.

The win puts Swiatek puts through to her fifth career Grand Slam semifinal, and third in Paris, where she'll face a player against whom she's been much less successful: Brazil's Beatriz Haddad Maia. The left-hander won the pair's only previous meeting, a three-set stunner in Toronto last summer, and became the first Brazilian woman in the Open Era to reach the Roland Garros semifinals with a three-set upset of Ons Jabeur earlier on Wednesday.

But that was on hard courts, and though Haddad Maia is a competent clay-courter, she'll come into Thursday's semifinal having played much more tennis than Swiatek. Swiatek has yet to lose a set this fortnight, totaling around five and a half hours on court, while Haddad Maia has logged a staggering 12 hours and 42 minutes.

With Aryna Sabalenka looming in the bottom half of the draw, Swiatek's win against Gauff also kept her in contention to retain the world No. 1 ranking after Roland Garros. Should she win against Haddad Maia, and Sabalenka lose to Karolina Muchova on Thursday, she'll stay on top.