Gauff won in straights when these two met on clay last year, but it could have gone either way. If the American is to prevail again, expect another close contest.

How many of these three Americans will still be standing by the end of Friday in Paris?

Is the 2016 French Open women's champion in danger of falling at the first hurdle against her Estonian opponent?

Before each day's play at the BNP Paribas Open, we'll preview three must-see matches.

The 20-year-old Pole was often below her best in her quarterfinal against Kaia Kanepi before problem-solving her way to a second major semifinal.

Meanwhile, Paula Badosa takes on Australian No. 2 Ajla Tomljanovic in her first Grand Slam as a Top 10 player.

“I really wanted this win and to have to come back from losing a bunch of games in a row is what I’m most proud of,” Keys told courtside interviewer Andrew Krasny.

There are 32 major titles represented in the bottom half, and just one on the top half. However, the task at hand will not be an easy one for the Croatian.

Based on how it all went, you’d think the 65th-ranked Estonian was the one who’d won this title 12 months ago.

Also, Feliciano Lopez rallied to win from two sets down for the fifth time in his career. Earlier, Shelby Rogers eased past Olga Danilovic with Novak Djokovic in the stands.