World number one Aryna Sabalenka saw her French Open title hopes vanish as she completely unravelled in a crushing quarter-final defeat by Diana Shnaider in yet another shock result at this year's tournament.
Sabalenka, a beaten finalist at Roland Garros last year, was 6-3 4-1 up before the momentum suddenly shifted and sparked an extraordinary comeback from Shnaider.
The Russian 25th seed, playing in her first Grand Slam quarter-final, reeled off 12 of the final 13 games to win 3-6 7-5 6-0 and complete a monumental upset.
Sabalenka had been the only Grand Slam singles champion remaining in an open women's draw and was the heavy favourite for the title.
Her defeat means Russian eighth seed Mirra Andreeva is the highest-ranked player left in the women's draw.
Windy conditions on Court Philippe Chatrier wreaked havoc with Sabalenka's powerful hitting and the Belarusian committed 57 unforced errors.
She was quick to voice her frustration as her performance dropped off, throwing her arms up, letting out guttural roars and unleashing her fury on her team.
It was reminiscent of her defeat in last year's final, when Sabalenka tallied a huge 70 unforced errors and let a one-set lead slip against Coco Gauff.
"Honestly I am speechless," Shnaider said in her post-match interview.
"She is the world number one, so I was just trying to do my best. I had to fight for every point."
Shnaider will face qualifier Maja Chwalinska in a semi-final few would have predicted, after the Pole defeated Anna Kalinskaya earlier on Wednesday.
Andreeva will face in-form 15th seed Marta Kostyuk of Ukraine in the other semi-final on Thursday.
Another upset in tournament of shocks
Aryna Sabalenka led Diana Shnaider by a double break in the second set
Like Jannik Sinner in the men's draw, Sabalenka was the favourite to win a maiden French Open title this year.
With four-time winner Iga Swiatek and reigning champion Coco Gauff knocked out relatively early, Sabalenka had her best chance to win a first Grand Slam away from the hard courts of New York and Melbourne.
But Sabalenka - like Sinner in his second-round defeat by Juan Manuel Cerundolo -surrendered a huge lead in yet another massive upset at this year's Roland Garros.
While Sinner struggled with cramping and dizziness in sweltering heat, Sabalenka only had herself to blame as she failed to adapt to the blustery conditions for a second year in a row.
Losses for Sinner, Sabalenka, Gauff and Novak Djokovic among others mean this is the first Grand Slam since the 1977 French Open that a former major champion has not featured in either the men's or women's semi-finals.
From complete control in the opening set and the start of the second, the 28-year-old Sabalenka faltered as Shnaider began to find her rhythm.
The left-hander caused all sorts of problems for the top seed with blistering forehand winners as Sabalenka struggled to put the ball in the court.
Losing the final set without winning a game was a sorry end, and Sabalenka made a hasty retreat off court after hugging Shnaider at the net.
Sabalenka will now be left to rue another missed opportunity - she has four major titles to her name but that is a puzzling return given she has reached the semi-finals in 12 of her past 13 Slam appearances.
In January's Australian Open final, she was 3-0 up in the deciding set before Elena Rybakina fought back to deny the Belarusian a third Melbourne title.
Now another major has slipped away from the world number one's grasp in a tournament that has been full of surprises.
BBC