Coco Gauff, 19, comes back to beat Russia’s Mirra Andreeva, 16, at the French Open

Not all that long ago, Coco Gauff was always the kid on the court, the unknown underdog, younger and less experienced than every opponent she faced on a big stage.

Now, still just 19, Gauff is well-versed in the professional tennis tour, already a Grand Slam runner-up in singles and doubles, and seeded No. 6 at this French Open. On Saturday at Roland Garros, the American was the veteran in Court Suzanne Lenglen under the cloudless sky, the one with the steady hand and steady head, in an all-teen showdown against Mirra Andreeva, a 16-year-old qualifier from Russia who is ranked 143rd and was making her debut appearance at a major tournament.

After a tight-as-can-be first set, one Gauff was two points from winning but eventually ceded, she grew her game and proved to be the better player. She pulled away to reach the fourth round in Paris with a