Former No. 1 Azarenka felt the impact of her sub-Top 50 ranking in March. In Indian Wells, she was pitted against Serena Williams in second round; in Miami, she faced Caroline Garcia after winning her opener.

In both cases, Azarenka couldn't overcome her seeded opponent, losing in straight sets. Building her ranking back up to the Top 32 will be critical to her prospects at this season's upcoming Slams, along with any other tournament she plays. In Monterrey, Azarenka is the fifth seed, and she took care of business in her opening match against Kato. (Highlights above.)

Now, Azarenka will see if she can make it through two rounds. Zarina Diyas awaits—and this time, Vika will be the favorite.

Monterrey: Sachia Vickery d. Alison Riske, 7-6 (6), 6-1


Away from Monterrey's Center Court, Riske and Vickery met in in all-American match-up in Mexico. And while the crowd was sparse, those who attended saw the 23-year-old display some of the form that helped her reach a career-high ranking in 2018.

Part of Vickery's rise last season was her play in Monterrey. She won her first seven sets at the hard-court tournament—including a 6-0, 6-3 win over second seed Magdalena Rybarikova—before falling to No. 4 seed Timea Babos in the semis. Next up for Vickery at this year's event is Nao Hibino.

Charleston: Danielle Collins d. Madison Brengle, 6-1, 6-3


Another all-American match-up took place in chilly Charleston, with the winner ensuring passage to the round of 32—and better playing conditions. Collins, who seems on the verge of winning her first WTA title after deep runs at big tournaments, is one of the better bets at the Volvo Car Open. She loves playing in the U.S., and the tournament has a history of breakthrough champions.

In the only green-clay tournament in tennis, Collins advanced with ease on Tuesday. She'll next face Aliona Bolsova Zadoinov on Wednesday afternoon.

Charleston: Sloane Stephens d. Sara Sorribes Tormo, 7-6 (4), 7-6 (4)


You can read about the top seed's opening-round test here. The defending champion should be commended for gutting through a tricky opponent in less-than-ideal conditions.

And she should be applauded for winning a back-and-forth rally with a deft volley, as seen above.