Ostapenko is the first player to beat five-time major champion Swiatek on every surface – once on grass, four times on hard courts and now once on clay.

Swiatek often struggles against Ostapenko’s powerful groundstrokes which rush her forehand and draw out the errors in her game.

The Pole came into the match with an 11-1 record in Stuttgart, having won the title in 2022 and 2023, but she could not fend off Ostapenko.

Ostapenko hit 29 winners to Swiatek’s 17, with eight double faults not helping Swiatek as Ostapenko attacked her second serve.

Ostapenko broke Swiatek’s serve three times to take the first set but was scrappier in the second, allowing Swiatek to level the match.

But Ostapenko won 12 of the first 15 point of the deciding set to take control, eventually taking the match on a long Swiatek forehand.

“She’s a great clay-court player but I won the French [Open] as well, so I can say the same thing about myself, ” the 27-year-old said.

“I have so much respect to her and her team but every time I step on the court with her, it’s a battle and I’m ready for it.”

Ostapenko will face a semi-final against Russia’s Ekaterina Alexandrova, who beat third seed Jessica Pegula 6-0 6-4.