Jack Sock retired from play Thursday after fainting in the middle of a match at the US Open.
CoCo Gauff, Naomi Osaka meeting in round 3 of U.S. Open
Both 15-year-old CoCo Gauff and world No. 1 Naomi Osaka advanced to the third round of the U.S. Open on Thursday, pitting two of the most famous names in the sport against each other. Will the match provide a look into tennis’ future in real time?