Defending champion Andy Murray could face top-seeded Novak Djokovic only in the semifinals at the U.S. Open, while Rafael Nadal and Roger Federer -- who have never played each other at Flushing Meadows -- might meet in the quarterfinals.
Maria Sharapova's return to WTA tournament play after more than a month away was short-lived following an upset loss to 17th-ranked American Sloane Stephens 2-6, 7-6 (5), 6-3 in the second round of the Western & Southern Open on Tuesday.
Even before Ryan Harrison broke his racket by spiking it on the Citi Open court or screamed "Oh, my God!" in exasperation, top-seeded Juan Martin del Potro was feeling pretty good about the way things were going Thursday.
Top-seeded John Isner figured he would struggle in his first match Thursday in the Atlanta Open. He had no idea he would barely beat 19-year-old wild-card entry Christian Harrison 7-6 (9), 4-6, 7-5 to avoid an upset and reach the quarterfinals.