Former champion Radek Stepanek was a round upset victim Thursday at the $531,000 SAP Open.
Belgian Steve Darcis bounced the fourth-seeded Czech 7-6 (7-4), 7-6 (7-2) on the hardcourts at HP Pavilion.
The world No. 29 Stepanek reached back-to-back finals here in 2008 and 2009, with his title coming in '09.
In other unseeded action, American Ryan Harrison took down compatriot Robby Ginepri, 6-3, 2-6, 7-6 (7-0), while Denis Istomin of Uzbekistan defeated American Michael Russell, 6-2, 6-2, in the final match of the day.
Harrison will face Kutrovsky in the quarterfinals and Istomin will take on three-time San Jose winner Andy Roddick on Friday.
This week's SAP Open champion will earn $95,860.