Williams defeated American Jared Hiltzik 6-4, 6-1 in his third-round match, while Sandgren beat Czech Republic's Libor Salaba 6-3, 6-3.
Williams' final qualifying round match has the potential to one of the best matchups of the entire tournament as the two-time All-American is set to play Virginia sophomore Alex Domijan. Williams and Domijan last met in the 2010 USTA/ITA National Intercollegiate Indoor Championships. With Domijan the top seed and unbeaten in his college career, Williams excelled in the critical moments and won 7-6, 7-6 in their only college clash.
Sandgren plays former Florida Gator Antoine Benneteau in his final match. Benneteau beat Sandgren last week at the Plantation (Fla.) Futures.
