American teenager Coco Gauff reached the French Open semi-final by beating compatriot Sloane Stephens 7-5 6-2.
It will be a first last-four appearance at a Grand Slam for the 18-year-old.
Gauff won the French Open junior title in 2018 - the same year Stephens finished runner-up to Simona Halep in the women's singles final.
She broke Stephens, 29, at the end of a tight first set and then took command of the second. Gauff will now face Martina Trevisan in the semis.
Trevisan, 28, also reached the last four at Roland Garros for a first time after overcoming Leylah Fernandez 6-2 6-7 (3-7) 6-3.