Russian third seed Dmitry Tursunov won his second career title with a 6-4 7-5 victory over Frank Dancevic of Canada at the Indianapolis championship on Sunday.
Blake will face fellow American Sam Querrey in the last eight after the teenager survived two match points before upsetting fifth-seeded Ivo Karlovic.
Defending champion James Blake and top seed Andy Roddick won their opening matches in straight sets at the Indianapolis Championships on Tuesday.
American Ginepri, who won the Indianapolis title in 2005 and reached the semi-finals last year, was upset by 83rd-ranked Michael Berrer of Germany 3-6 6-2 6-1.