Americans Jack Sock and Rajeev Ram advanced to the quarterfinals of the Hall of Fame Tennis Championships on Wednesday.

Fourth-seeded Sock rallied past Lukas Lacko of Slovakia 3-6, 7-6 (4), 6-4. Ram defeated Yuichi Sugita of Japan 6-4, 6-3, a day after upsetting top-seeded John Isner.

The 31-year-old Ram returned the various slices, lobs and other change-of-pace shots offered by Sugita. The 161st-ranked Ram last won the Newport title in 2009.

The 22-year-old Sock, ranked 39th, needed two hours to advance in humid conditions on center court.