Maja Chwalinska vs Alycia Parks — R16 — Monterrey Open

Seeded third and made a 60 percent favorite by the betting market, Chwalinska converted both break points she earned all match and lost anyway; a third chance never came. Parks manufactured six of her own and took four, leaning on the weapon that has always defined her game: 10 aces to one, six of them in the closing set, with 11 of 13 service games held. Her break in game 5 of the third, for 4-1, put it beyond reach at 1 hour 49 minutes. That is a second straight recovery from a set down this week at the Monterrey Open for the 63rd-ranked American, who moves into the quarterfinals.