Querrey, who entered the week ranked 99th in the world, is on a climb back up the rankings after right elbow surgery last June.
Top-seeded John Isner was scheduled to play in Thursday night’s featured match against fellow American Donald Young.
Others moving to the quarterfinals were Lukasz Kubot of Poland and Jurgen Melzer of Austria.
By John Solomon
How the government's punishing of the exposure of official wrongdoing can linger for years
Independent voices from the TWT Communities
Weekly agitation from a columnist who many believed to be one of the least likely to become known as a Conservative Republican.
Happiness is attainable. Morning to night. I love to teach, deal with folks that have an issue and really wish to tackle it and write.
This column will cover anything that has anything remotely to do with the game of baseball, from the game itself to mid-summer trades to offseason moves.
Television commentary, reviews, news and nonstop DVR catch-up.
Benghazi: The anatomy of a scandal
Vietnam Memorial adds four names
Cinco de Mayo on the Mall
NRA kicks off annual convention