Sousa defeated Tursunov 6-4, 6-3, winning more than two-thirds of the points on serve and cashing in three of his five break opportunities. Sousa had two breaks in the first set and recorded the only break in the second to earn a spot in the tournament semifinals.
Michal Przysiezny beat seventh-seeded Lukas Rosol 7-6 (9-7), 1-6, 6-3 and Guillermo Garcia-Lopez ousted No. 8-seeded Denis Istomin 6-2, 6-4 -- leaving sixth-seeded Ernests Gulbis the only seeded player to escape the spate of upsets Friday.
Gulbis rolled by Roberto Bautista Agut 6-1, 6-2 in 60 minutes. He dropped eight points on serve and didn't face a break point.
Garcia-Lopez had two breaks in each set in his match with Istomin while Przysiezny had enough energy left in the third set to fire off five aces and get the only break of the set.
Gulbis and Przysiezny, who have split their two previous meetings, play in the first semifinal Saturday. Garcia-Lopez and Sousa have never before met on the court.