PARIS -- The rain finally held off at the French Open, so Petra Kvitova rained down aces instead.
She delivered six of them, taking her tournament-leading tally to 24, as the two-time Wimbledon champion reached her first semifinal at Roland Garros since 2012 and first at any Grand Slam since her run to the final of the 2019 Australian Open.
Her semifinal opponent will be Sofia Kenin, the Australian Open champion who has been pushed to three sets in all but one of her five matches so far in Paris, including her 6-4, 4-6, 6-0 quarterfinal win Wednesday over fellow American Danielle Collins.
"I like winning in three sets," said the fourth-seeded Kenin, whose only previous Grand Slam semifinal was on her way to winning at Melbourne Park. "I'm really proud of myself."
On the other end of the easier 6-3, 6-3 victory for seventh-seeded Kvitova was Laura Siegemund, an unseeded German player in her first Grand Slam quarterfinal. The first set, especially, flashed by in a blur of left-handed serves that Siegemund couldn't reach or capitalize on and powerful groundstrokes she had no answer to.
For Kvitova, her first return to the semifinals in eight years marks another step in her recovery from a traumatic stabbing by an intruder at her home in the Czech Republic in December 2016. All five fingers on the left hand that she uses to hold her racket were injured in the knifing, and doctors told her she might never be competitive again.
"It's another miracle," she said.
Against Kenin, Collins proved to be her own enemy, double-faulting at 0-40 to give her opponent the only break of serve in the first set and again at the start of the third set, also at 0-40, having just fought furiously in the second set to level the match at a set apiece.
Collins, who'd previously not advanced beyond Round 2 in Paris, received medical treatment as she trailed 4-0 in the final set and appeared limited in her movements.
"I was kind of praying for a miracle at the end there," she said. "I can walk away saying that I gave it my all."
Kvitova hit all six of her aces in the first set, in which she also never faced a break point and won 93% of the points on her first serve. Her fastest serve was clocked at 168 kph (104 mph). She brought up two set points with another ace and converted the first with a clean forehand winner.
Playing without sleeves or leggings under the pale autumn sun on Court Philippe Chatrier, Kvitova has yet to drop a set on the Paris clay.
"Right now, it's my lucky place," she said.
The story was unchanged at the start of the second set, with Siegemund broken again in the first game.
But glitches then started creeping into Kvitova's game.
Back-to-back double-faults in the fourth game from the 30-year-old Czech gave Siegemund her first break point of the match.
Kvitova saved that and two others that followed. But Siegemund earned another with a forehand passing shot that sailed past Kvitova at the net and then leveled the set at 2-2 when Kvitova netted a backhand.
Then followed three erratic games in which neither player was able to hold serve and an altercation between Siegemund and the chair umpire who ruled that she had been too slow to serve.
"I know I am slow," said Siegemund, who was given a time violation. "I'm trying my best to be faster. And I think I am also much faster than I was in the past."
The 32-year-old Siegemund, the oldest debutant Grand Slam quarterfinalist since Norma Marsh at the 1971 Australian Open, complained of lower-back pain after she was broken in the fifth game of that topsy-turvy set and got treatment from the physio.
In the next game, another double-fault from Kvitova gifted Siegemund a break point that enabled her to level again at 3-3.
But the last three games were all one-way for Kvitova. She broke Siegemund to love in the seventh game, helped by a double-fault that brought up three break points, and then held to love to leave Siegemund facing the pressure of serving at 5-3 to stay in the match. It proved too much for her: She double-faulted on match point.