After Mirra Andreeva's historic Roland Garros triumph, Maria Sharapova took to social media to laud her compatriot's mindset. The former world No. 1 highlighted the drive that already defines the young star.

Bent over with her hands covering her face, her knees getting dirtied on the red clay court, Mirra Andreeva was celebrating — processing might be the more appropriate word — how she had finally overco...