Sandgren faces 2010 NCAA champion Bradley Klahn of Stanford. Williams will play 10th-seeded Rik De Voest in an evening match.
While Sandgren and Klahn have never faced each other in a collegiate or ITF event, Williams and De Voest have a recent history. De Voest beat Williams 7-6 (5), 5-7, 7-6 (6) in a very close opening match at the 2010 Knoxville Challenger.
The Vols duo would have to win four matches to reach the main draw of the US Open, the final Grand Slam of the professional tennis circuit. Both played in the Junior US Open as teenagers.
