Iga Swiatek stunned by teenager Mirra Andreeva in Stuttgart Open quarter-final as Coco Gauff loses to Karolina Muchova

Andreeva, now world No. 9 after an impressive rise to prominence, came from a set down against the six-time Grand Slam champion to win 3-6 6-4 6-3.

Swiatek was third seed and among the favourites to win on the clay in Stuttgart, having lifted the French Open title four times.

But she came up against a resolute opponent in Andreeva, who came out on top in two hours and 36 minutes.

Swiatek appeared to be on course for victory after capitalising on some unforced errors from Andreeva in the opening set.

The 18-year-old fought back to take the second before Swiatek took a two-game lead early in the decider.

But Andreeva broke twice in response and secured victory to set up a semi-final against Elena Rybakina or Leylah Fernandez.

"I think my baseline game ⁠was fine, ​and I see progress there compared to the ​last tournaments. But for sure, overall, it wasn't enough," Swiatek said.

”When you play against someone so experienced - she’s won so many tournaments, I can’t even count how many Slams and Masters she has - you know it’s going to be tough,” Andreeva said.

”I feel confident in my game. I’ve won a couple of matches in Linz and I’ve been playing well here too. I just kept telling myself that no matter what happens, I have to keep fighting and believe I can win from any score.

”I was just trying to be fearless. When I get tight, I tend to just put the ball in and wait for mistakes. Against someone like her, that’s not going to work. So I forced myself to go for my shots and finish the match on my own terms.”

Elsewhere, Karolina Muchova advanced to the last four with a memorable 6-3 5-7 6-3 win over second seed Coco Gauff.

Muchova, who will play Elina Svitolina in the semi-finals, had never beaten Gauff in six previous meetings.

"It was a great fight. I'm just happy that I finally, finally beat her," Muchova said. "This was actually our first match on a clay court. On clay we were 0-0 in the matches - I tried to keep it positive."

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